Earthworms and Vermicomposting: Species, Procedures and Crop Application 9819989523, 9789819989522

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Sohan Singh Walia Tamanpreet Kaur

Earthworms and Vermicomposting Species, Procedures and Crop Application

Earthworms and Vermicomposting

Sohan Singh Walia • Tamanpreet Kaur

Earthworms and Vermicomposting Species, Procedures and Crop Application

Sohan Singh Walia School of Organic Farming Punjab Agricultural University Ludhiana, Punjab, India

Tamanpreet Kaur School of Organic Farming Punjab Agricultural University Ludhiana, Punjab, India

ISBN 978-981-99-8952-2    ISBN 978-981-99-8953-9 (eBook) https://doi.org/10.1007/978-981-99-8953-9 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore Paper in this product is recyclable

Preface

Vermicomposting is a sustainable and eco-friendly practice that transforms organic waste into a valuable resource for gardening, agriculture, and environmental stewardship. In this book, we embark on a journey to explore the remarkable process of vermicomposting and its significance in today’s world. Vermicomposting, often referred to as “worm composting,” stands as a shining example of nature’s recycling system at work. It harnesses the power of earthworms to convert kitchen waste, garden waste, and various organic materials into nutrient-rich worm castings—a natural fertilizer and soil conditioner of unparalleled quality. As we delve deeper into the world of vermicomposting, you will discover its many facets, from the ecological benefits of reducing landfill waste to the practical advantages of enhancing soil fertility and structure. Whether you are a seasoned gardener seeking ways to enrich your plants or someone interested in minimizing your environmental footprint, vermicomposting offers a practical and rewarding solution. Throughout this book, we will navigate the ins and outs of vermicomposting, from selecting the right worms to designing a suitable bin or system and from troubleshooting common issues to reaping the bountiful harvest of nutrient-dense castings. As we embark on this vermicomposting journey together, this book aims to provide you with a comprehensive understanding of the principles, techniques, and benefits of vermicomposting. Whether you are a seasoned gardener looking to enrich your soil naturally or a newcomer interested in sustainable waste management, you will find valuable insights within these pages. Currently, there is a limited availability of reference books catering to the needs of students in this specialized area. This book presents the subject matter in a well-­ structured and coherent manner, aiming to enhance students’ comprehension and ensure a consistent learning experience. We believe that this book will prove immensely valuable to students, teachers, and extension personnel alike. This book is the result of a deep passion for vermicomposting and a commitment to sharing knowledge that empowers individuals and communities to make a positive impact on our planet. We hope you find inspiration within these pages and embark on your own vermicomposting adventure, contributing to a greener and more sustainable world.

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We are open to receiving suggestions for further enhancing the content of this book. Your input and feedback are highly appreciated as they will help us continually improve and refine the material. Together, we can strive for excellence in this field of study. Ludhiana, Punjab, India Ludhiana, Punjab, India 

Sohan Singh Walia Tamanpreet Kaur

Contents

1

Earthworms and Vermicomposting����������������������������������������������������������   1 1.1 Introduction����������������������������������������������������������������������������������������   1 1.1.1 Vermicomposting��������������������������������������������������������������������   2 1.2 Origin and Evolution��������������������������������������������������������������������������   3 1.3 Distribution of Earthworm������������������������������������������������������������������   3 1.4 Size of Earthworm������������������������������������������������������������������������������   4 1.5 Food and Feeding Habits��������������������������������������������������������������������   5 References����������������������������������������������������������������������������������������������������   5

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Anatomy of Earthworms��������������������������������������������������������������������������   7 2.1 Body Structure������������������������������������������������������������������������������������   7 2.1.1 Earthworm Body��������������������������������������������������������������������   7 2.1.2 Shape, Size, and Color of Cocoons����������������������������������������  15

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 Earthworms, Their Species, and Biological Features ����������������������������  17 3.1 Earthworm Species ����������������������������������������������������������������������������  21 3.1.1 Redhead Worm������������������������������������������������������������������������  21 3.1.2 Common Earthworm��������������������������������������������������������������  22 3.1.3 Green Worm����������������������������������������������������������������������������  23 3.1.4 European Night Crawler ��������������������������������������������������������  24 3.1.5 Brandling Worm����������������������������������������������������������������������  24 3.1.6 Giant Gippsland Earthworm ��������������������������������������������������  25 3.1.7 Washington Giant Earthworm������������������������������������������������  27 3.1.8 Gray Worm������������������������������������������������������������������������������  27 3.1.9 Composting Worm������������������������������������������������������������������  28 3.1.10 African Night Crawler������������������������������������������������������������  28 3.2 Biological Features of Earthworm������������������������������������������������������  30 3.3 The Morphology and Anatomy of the Earthworm Are Discussed Below��������������������������������������������������������������������������  30 3.3.1 Anatomy of Earthworm����������������������������������������������������������  31 3.3.2 Digestive System��������������������������������������������������������������������  31 3.3.3 Circulatory System�����������������������������������������������������������������  31 3.3.4 Respiratory System ����������������������������������������������������������������  31 3.3.5 Excretory System��������������������������������������������������������������������  31

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3.3.6 Nervous System����������������������������������������������������������������������  32 3.3.7 Sensory System����������������������������������������������������������������������  32 3.3.8 Reproductive System��������������������������������������������������������������  32 3.3.9 Multiplication of Worms ��������������������������������������������������������  32 3.3.10 Earthworm Sexuality��������������������������������������������������������������  33 3.3.11 Ready for Reproduction����������������������������������������������������������  34 3.3.12 Copulation and Fertilization ��������������������������������������������������  34 3.3.13 No Partner Needed������������������������������������������������������������������  34 References����������������������������������������������������������������������������������������������������  36 4

 Vermitechnology: History and Its Applications��������������������������������������  37 4.1 History������������������������������������������������������������������������������������������������  38 4.2 Wastes Utilized in Vermitechnology ��������������������������������������������������  38 4.3 Earthworms Used in Vermitechnology ����������������������������������������������  39 4.3.1 Earthworm Species Suitable for Waste Degradation��������������  39 4.4 Role of Earthworms in Vermitechnology��������������������������������������������  40 4.4.1 Effects of Earthworms on ������������������������������������������������������  40 4.5 Applications of Vermitechnology ������������������������������������������������������  42 4.6 Issues Related to Vermitechnology ����������������������������������������������������  43 4.7 Vermitechnology in Other Countries��������������������������������������������������  44 4.8 Vermitechnology in India��������������������������������������������������������������������  46 4.9 Vermitechnology in Northeast India ��������������������������������������������������  48 4.10 Recent Works Related to Vermitechnology����������������������������������������  49 4.10.1 Aerobic Sponge Method Vermitechnology for Macro-Level Conversion of Organic Garbage������������������  49 4.10.2 Treatment of Agricultural Wastes with Biogas: Vermitechnology ��������������������������������������������������������������������  50 4.10.3 Assessment of Different Organic Supplements for Degradation of Parthenium Hysterophorus by Vermitechnology����������������������������������������������������������������  50 4.10.4 Application of Vermitechnology in Aquaculture��������������������  50 4.10.5 Vermitechnology for Organic Waste Management and Sustainable Agriculture (Gopi 2017; Chattopadhyay 2017)��������������������������������������������������������������  51 4.11 Future Prospects����������������������������������������������������������������������������������  51 References����������������������������������������������������������������������������������������������������  51

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 Role of Earthworms in Vermicomposting������������������������������������������������  55 5.1 Earthworm Species Suitable for Vermicomposting����������������������������  56 5.2 Organic Matter and Earthworms in the Soil ��������������������������������������  56 5.3 Soil Nitrogen and Earthworms������������������������������������������������������������  57 5.4 Soil Phosphorus and Earthworms ������������������������������������������������������  57 5.5 Heavy Metals and Vermicomposting��������������������������������������������������  58 References����������������������������������������������������������������������������������������������������  59

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Different Sources of Vermicompost: Vermicomposting from Household Waste—Vermicomposting from Farm Waste�������������  61 6.1 Different Sources of Vermicompost����������������������������������������������������  61 6.2 Vermicomposting from Household Waste������������������������������������������  64 6.2.1 Method������������������������������������������������������������������������������������  64 6.3 Vermicomposting from Farm Waste ��������������������������������������������������  64 6.3.1 Methods����������������������������������������������������������������������������������  64 6.4 Different Sources and Preparation of Vermicompost��������������������������  67 References����������������������������������������������������������������������������������������������������  69

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Preparation of Vermicompost ������������������������������������������������������������������  73 7.1 Introduction����������������������������������������������������������������������������������������  73 7.2 Sequential Method of Composting ����������������������������������������������������  73 7.3 Mechanism of Earthworm Action������������������������������������������������������  76 7.4 Vermicomposting Systems������������������������������������������������������������������  77 7.4.1 Windrow System��������������������������������������������������������������������  77 7.4.2 Wedge System������������������������������������������������������������������������  78 7.4.3 Container System��������������������������������������������������������������������  78 7.4.4 Continuous Flow System��������������������������������������������������������  80 7.5 Maintaining Continuous Flow������������������������������������������������������������  81 7.6 Feeding Rates��������������������������������������������������������������������������������������  81 7.7 Excessive Heating ������������������������������������������������������������������������������  82 7.8 Method for Preparation of Vermicompost from Paddy Straw/Waste Maize Silage������������������������������������������������������������������  83 7.9 Processing: Time and Acceleration����������������������������������������������������  83 7.10 Maturity and Stability ������������������������������������������������������������������������  84 7.11 Composting v/s Vermicomposting������������������������������������������������������  84 7.12 Acceleration Process��������������������������������������������������������������������������  84 7.12.1 Organic Nutrients and Other Additives����������������������������������  84 7.12.2 Effective Micro-organisms (EM)��������������������������������������������  85 7.13 Domestic Waste Processing Systems��������������������������������������������������  85 7.14 Points to Be Considered When Making Compost������������������������������  85 References����������������������������������������������������������������������������������������������������  87

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 Influence of Vermicompost on Soil Health����������������������������������������������  89 8.1 Introduction����������������������������������������������������������������������������������������  89 8.2 Influence of Physiochemical Properties of Soil����������������������������������  89 8.3 Influence of Vermicompost on Biological Properties of Soil�������������  91 8.4 Modification in Physico-Chemical Characteristics of Feed Waste Through Vermicomposting������������������������������������������  91 8.5 pH and Electrical Conductivity (EC)��������������������������������������������������  91 8.6 Nitrogen����������������������������������������������������������������������������������������������  92 8.7 Organic Carbon and C:N Ratio����������������������������������������������������������  93 8.8 Phosphorus������������������������������������������������������������������������������������������  94 8.9 Beneficial Role of Vermicompost in Fruit Crops��������������������������������  95

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8.10 Beneficial Role of Vermicompost in Vegetable Crops������������������������  97 8.11 Nutrient Recovery from Kitchen Bio-Waste��������������������������������������  98 8.12 Integration of Composting and Vermicomposting������������������������������  99 8.13 Importance of Vermicompost��������������������������������������������������������������  99 8.14 Environmental Applications of Vermicompost ���������������������������������� 100 References���������������������������������������������������������������������������������������������������� 101 9

Harvesting of Vermicompost�������������������������������������������������������������������� 109 9.1 Introduction���������������������������������������������������������������������������������������� 109 9.2 Vermicompost ������������������������������������������������������������������������������������ 109 9.2.1 Materials for Preparation of Vermicompost���������������������������� 110 9.2.2 The Five Essentials ���������������������������������������������������������������� 112 9.2.3 Harvesting Vermicompost������������������������������������������������������ 112 9.2.4 Harvesting Earthworm������������������������������������������������������������ 113 9.2.5 Storing and Packing of Vermicompost������������������������������������ 115 9.2.6 Precautions During the Process���������������������������������������������� 116 Reference ���������������������������������������������������������������������������������������������������� 116

10 By-Product and Value-Added Products �������������������������������������������������� 117 10.1 Vermiwash���������������������������������������������������������������������������������������� 117 10.1.1 Steps for Preparation������������������������������������������������������������ 118 10.2 Vermicompost Tea���������������������������������������������������������������������������� 119 10.3 Vermimeal ���������������������������������������������������������������������������������������� 119 10.4 Enriched Vermicompost�������������������������������������������������������������������� 120 10.5 Pelleted Vermicompost��������������������������������������������������������������������� 120 References���������������������������������������������������������������������������������������������������� 121 11 Problems in Handling Vermicompost������������������������������������������������������ 123 11.1 Temperature�������������������������������������������������������������������������������������� 123 11.2 Aeration�������������������������������������������������������������������������������������������� 124 11.3 Acidity (pH)�������������������������������������������������������������������������������������� 124 11.4 Pests and Diseases���������������������������������������������������������������������������� 124 11.5 Odor�������������������������������������������������������������������������������������������������� 127 12 Importance  of Application of Vermicompost in Cereal, Fruit and Vegetable Crops������������������������������������������������������������������������ 129 12.1 Rice Crop������������������������������������������������������������������������������������������ 130 12.2 Uses of Vermicompost in Urban Areas �������������������������������������������� 132 12.3 Landfilling���������������������������������������������������������������������������������������� 132 12.4 Incineration �������������������������������������������������������������������������������������� 133 12.5 Animal Feed�������������������������������������������������������������������������������������� 133 References���������������������������������������������������������������������������������������������������� 133 13 Beneficial  Role of Vermicompost: Nutrient Content in Vermicompost and Success Stories������������������������������������������������������ 135 13.1 Beneficial Role of Vermicompost ���������������������������������������������������� 136 13.2 Nutrient Content in Vermicompost �������������������������������������������������� 139

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13.3 Success Stories���������������������������������������������������������������������������������� 141 13.3.1 Success Story of Prateek Bajaj �������������������������������������������� 141 13.3.2 Success Story of Karan Sikri (Kurukshetra’s Young Farmer)���������������������������������������������������������������������������������� 142 13.3.3 Success Story of Bhikhari Mehta (Kumar et al. 2017) �������� 143 13.3.4 Success Story of Ravuri Suresh Kumar (Devi and Kumar 2020)�������������������������������������������������������� 144 References���������������������������������������������������������������������������������������������������� 145 14 Conclusion�������������������������������������������������������������������������������������������������� 147

About the Authors

Sohan Singh Walia  is working as Director in the School of Organic Farming, Punjab Agricultural University, Ludhiana. He started organic farming research as a pioneer work at PAU, Ludhiana, as Ph.D. student (2001–2004) and then worked on organic farming and integrated farming systems in All India Coordinated Research Project on Integrated Farming Systems and All India Network Project on Organic Farming. He has to his credit more than 450 research and extension publications, nine books, ten teaching manuals, seven extension folders. and 22 book chapters. He has handled 24 research projects and is currently handling five research projects. The chapter on organic farming and integrated farming system in package of practices was included during 2004–2005 and 2017–2018, respectively. Sixty-eight recommendations have been included in the package of practices for mass adoption by the Punjab farmers, especially resource conservative cropping systems, nine organic farming based cropping systems, and production technology of cultivation of direct seeded rice. In addition, he was involved in technologies regarding application of consortium in sugarcane, turmeric, potato, onion, maize, wheat crops; integrated nutrient management in maize/soybean; rice residue management for the mass scale adoption under Punjab conditions. He developed Integrated Farming System Research Model comprising dairy, fishery, horticulture, vegetables, agro-forestry, and vermicomposting. He has been involved in teaching of 93 courses. He has guided four Ph.D. and eleven M.Sc. students as major advisor. He has organized 20 training programs, delivered 62 invited lectures, 350 training lectures, and 52 TV and radio talks. He has attended ten international and 75 national conferences/seminars/workshops. He was appreciated for outstanding work on integrated (2007–2017) and organic farming during QRT review (2012–2017). He is Recipient of Best Organic Farming Centre Award (2019) by ICAR; Dr M S Randhawa Best Book Award (2017); Fellow, Indian Ecological Society (2016); Gold medal from Society of Recent Development in Agriculture at International Conference (2013); ISA Best Paper Award along with cash prize of Rs 5000/- from Indian Society of Agronomy (2011) for paper entitled “Alternate Cropping Systems to Rice-Wheat for Punjab”; ISA P.  S. Deshmukh Young Agronomist Award (2005) by Indian Society of Agronomy; and Fellow, Society of Environmental Sciences (2004). The AICRP on Integrated Farming System, Ludhiana center received the Best Centre Award (2014) from ICAR-Indian Institute of Farming Systems Research, Modipuram, Meerut. He also received Dr. Gurbaksh Singh Gill Gold Medal, Merit Certificate for M.Sc. (agronomy); S.S. Labh Singh Gold Medal and Merit Certificate for B.Sc. Agri. (Hons.). He has acquired advance training in rice production systems from School of Agriculture, Food and Wine, University of Adelaide, South Australia. Tamanpreet Kaur  is working as Senior Research Fellow (2018–till date) under project entitled “All India Coordinated Research Project on Integrated Farming Systems” at School of Organic Farming, Punjab Agricultural University, Ludhiana. She holds a M.Sc. in agriculture from Punjab Agricultural University, Ludhiana. Her area of interest is on integrated farming systems. She has eight research papers, 13 extension articles, one booklet on integrated farming systems, and three book chapters. xiii

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Earthworms and Vermicomposting

1.1 Introduction Vermicomposting is the type of composting in which certain species of earthworms are used with the objective of organic waste conversion to produce superior quality manure to feed our “organic matter hungry” soils. A large amount of agricultural waste is being generated annually. The handling of organic solid waste has become more complicated and meticulous due to the quickly increasing population, intensive farming, and industrialization. Presently, worldwide annual municipal solid waste production is estimated to be 2.01 billion tons. The World Bank estimates overall waste generation will increase to 3.40 billion metric tons by 2050. It has been estimated that 13.5% of waste being produced nowadays is recycled and 5.5% is composted. According to “What a Waste 2.0,” a newly published report from the World Bank between one-third and 40% of the waste generated worldwide is not managed appropriately and rather dumped or openly burned. Currently in India, around 500 million tons of agro-industrial and agricultural residues are being reported yearly. Around 70% of these residues are utilized as fuel for domestic and industrial sectors, fodder, and other economic objectives (Ministry of New and Renewable Energy). In Punjab, 21 million tons of rice straw and 17 million tons of wheat straw are generated annually. More than 80% of paddy straw and almost 50% of wheat straw generated in the state are being burned every year in the field. It has been evaluated that burning of 1 tone of paddy straw accounts for 5.5 kg nitrogen, 2.3 kg of phosphorus, 25 kg of potassium, 1.2 kg sulfur, 50–70% micro-nutrients absorbed by rice, and 400 kg of carbon. Composting and vermicomposting are the most widely recognized methods for biologically stabilizing solid waste. Vermicomposting, in particular, raises several important considerations. It not only contributes to environmental pollution monitoring but also results in the production of high-quality, consistently uniform products, surpassing the outcomes of traditional composting.

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_1

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Earthworms and vermicomposting are fascinating subjects in the realm of ecology, agriculture, and sustainable waste management. Earthworms, often underestimated creatures, play a pivotal role in improving soil health and the environment. Vermicomposting, however, is a sustainable practice that harnesses the power of earthworms to transform organic waste into nutrient-rich compost. Earthworms belong to the class Oligochaeta and are found in diverse habitats around the world, from forests to gardens to agricultural fields. They are known for their unique ability to burrow through the soil, which not only aerates it but also helps in the decomposition of organic matter. Earthworms come in various species, with some adapted to specific environments and tasks. The key characteristics of earthworms include their segmented bodies, which are covered in tiny bristle-like structures called setae. These setae help them grip and move through the soil. Earthworms are also hermaphroditic, meaning they have both male and female reproductive organs. During mating, they exchange sperm with another worm, which later leads to the development of cocoons containing fertilized eggs.

1.1.1 Vermicomposting Vermicomposting is described as “bio-oxidation and stabilization of organic material involving the joint action of the earthworm and mesophilic micro-organisms” (Aira et al. 2007). It is a sustainable and eco-friendly method of converting organic waste materials into nutrient-rich compost using earthworms. It involves feeding organic waste, such as kitchen scraps, yard waste, and even certain paper products, to a colony of specially selected composting worms, most commonly the red wigglers (Eisenia fetida and Eisenia andrei). Under suitable conditions, worms feed almost on anything that was once living and pass it through their digestive system and give out in a granular form called cocoons and results in the reduction of volume by 40–60% which is called vermicompost. Vermicompost produced by the activities of earthworms is rich in macro and micro-nutrients, vitamins, growth hormones, enzymes such as proteases, amylases, lipase, cellulose, and immobilized microflora (Ismail 1995). Vermicompost, the earthworm excrement, called castings, can play a major role in improving the physical, chemical, and biological properties of soil. Earthworm’s digestive tract contains chemical secretions that play a major role in the breakdown of soil and organic matter which results in the castings that include more nutrients in the plant available form. Earthworms leave the soil 5–11% richer in essential plant nutrients of nitrogen, phosphorus, and potassium than when they first ingest it. Vermicomposting offers numerous benefits as listed below: 1. High-Quality Compost: The compost produced through vermicomposting is exceptionally nutrient-rich, making it an ideal soil conditioner and fertilizer. 2. Waste Reduction: It reduces the amount of organic waste that ends up in landfills, decreasing methane emissions and helping combat climate change. 3. Soil Health: Vermicompost improves soil structure, moisture retention, and nutrient availability, promoting healthier plant growth.

1.3  Distribution of Earthworm

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4. Sustainability: It is a sustainable practice that can be implemented on a small or large scale, making it suitable for both individual households and commercial agriculture. 5. Cost-Effective: Vermicomposting is cost-effective, as it utilizes organic waste materials that would otherwise, require disposal. 6. Reduced Need for Chemical Fertilizers: The nutrient-rich vermicompost can reduce the need for chemical fertilizers, which can have negative environmental impacts. Therefore, earthworms and vermicomposting are intertwined in a mutually beneficial relationship. Earthworms, with their remarkable ability to decompose organic matter and improve soil quality, are at the heart of vermicomposting’s success. This eco-friendly practice not only reduces waste but also contributes to healthier soils and a more sustainable environment, making it a valuable technique for anyone interested in sustainable agriculture and waste management.

1.2 Origin and Evolution Not much scientific information is available on origin and evolution of earthworms. This is because body of earthworm is very soft and decays quickly. Due to these reasons fossil formation had been difficult and fossils have not been found to appropriately interpret origin and evolution of earthworms. However, fossilizable parts or organelles on earthworm body are “chaetae” or setae. These are chitinous, but with these organelles, tracing of evolution is extremely difficult. However, shape, arrangement, and number of “setae” comprise important taxonomic, character for identification of existing earthworms. There are indirect interpretations on evolution due to want of fossils. Thus, two school of thoughts are widely referred by J. Stephenson in 1930 that origin of earthworms is around 120 million years ago, i.e., the origin of worms is after origin of dicotyledonous plants. Other school opined that origin of worms is prior to origin of dicotyledonous plants. This was based on finding of vascular bundles of ferns in fossils of some worms. This school supported view that Annelids originated in Precambrian and Cambrian periods, i.e., around 570 million years ago. It is also opined that earlier worms had their origin in water and slowly got adapted to life on land.

1.3 Distribution of Earthworm The distribution of earthworms is result of the activities of their ancestors, migratory capabilities of earthworms and their ability to survive in old and new environment. Earthworms are widely distributed in most ecosystems of the world except in sea, desert, and areas without vegetation or in permanent snowy areas. There are two types of earthworms depending upon criteria of “adaptability,” namely

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(i) Peregrine species (ii) Endemic species Peregrine species are highly adaptative and are widely distributed. Such species are numerous exotic species like Eisenia foetida, the sewage worm, and Eudrilus eugeniae, the African Night Crawler, which have got established with human’s efforts in countries other than their natural homes. Such species are called Peregrine. Endemic species are less adaptive and have remained indigenous or localized unless specifically maintained by human in habitats other than natural homes. Presently, many endemic species are being maintained in different countries for vermiculture and some are gradually getting distributed via cocoons transported with plants and vermicompost. Some new or introduced species can dominate over local ones or endemic species in natural environment due to their adaptability. Natural distribution and population of earthworms are largely affected with habitat destruction. These involve activities like ploughing, use of chemical fertilizers, discharge of industry chemical waste, use of fungicides, insecticides, weedicides, etc. These modern agriculture production technologies are applied for higher agricultural production to meet the demand of growing population and livestock. Therefore, we have to adopt eco-friendly approaches, beneficial faunal activities for maintenance of agro-ecology. In natural environments, earthworm populations are not evenly spread, and their distribution fluctuates both horizontally and vertically. The horizontal arrangement of earthworms is influenced by numerous factors, including soil temperature, moisture levels, mineral composition, aeration, food availability, reproductive capabilities, and their adaptability to the surroundings. Conversely, the vertical distribution of earthworms varies throughout the seasons, influenced by factors such as habitat preferences and feeding behavior. Some earthworms inhabit the soil’s surface, while others create burrows within the soil, their choice depending on their particular distribution patterns. Some species burrow deep in soil, e.g., Drawida grandis has burrow depths of 2.7–3.0 m.

1.4 Size of Earthworm The body size of earthworms greatly varies. Among Indian species, Bimastos parvus, Dichogaster saliens, Microscolex phosphoreus are even less than 2 cm long. Some southern species like Drawida nilamburensis and Drawida grandis may be up to 1 m length. Australian species, viz. Megascolides australis can be of 4 m length. However, the length of South African species, Microchaetus microchaetus is reported to be 7 m and has the distinction of world’s largest earthworm.

References

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1.5 Food and Feeding Habits Earthworms primarily consume organic materials such as off-farm waste found in agricultural settings, dairy facilities, leaf litter, humus, compost by-products, weeds, and vegetable peels, among others. These earthworms obtain their nutrition from micro-organisms and decaying organic matter within the soil. Earthworms that reside on the soil’s surface typically feed on leaf litter, while those burrow into the soil ingest soil particles and obtain nourishment from the soil itself. The quantity and quality of available food sources play a pivotal role in determining factors like the size of the earthworm population, species diversity, growth rates, and reproductive potential. Interestingly, there is one South African earthworm species known for its carnivorous habits, preying on other worms. The daily consumption or intake of food can vary from one species to another, generally ranging from 100 to 300 mg per gram of the earthworm’s body weight. On an estimate, an earthworm has the capacity to ingest between 8 and 20 g of cow dung per year. To illustrate, if we consider an earthworm population density of 120,000 adults per hectare, the annual consumption of cow dung would amount to approximately 17.20 tonnes per hectare. This represents a relatively high turnover rate of organic matter compared to the organic matter conversion and soil mixing achieved through the earthworms’ feeding and casting activities. An alternative estimate, as proposed by Satchell, suggests that in a temperate deciduous forest where annual leaf fall totals approximately 3 tonnes per hectare per year, earthworms can consume (as both food and castings) this amount within just 3 months. This consumption is based on an average daily intake of 27 mg of leaf litter per gram of the earthworm’s body weight. This high rate of organic matter recycling is exceptionally efficient, particularly for forestry and the growth of related vegetation. These estimates collectively emphasize the significant role played by earthworms as vital components of soil biology, actively contributing to the mixing and incorporation of organic matter into the soil.

References Aira M, Monroy F, Dominguez J (2007) Earthworms strongly modify microbial biomass and activity triggering enzymatic activities during vermicomposting independently of the application rates of pig slurry. Sci Total Environ 385:252–261 Ismail S (1995) Earthworms in soil fertility management. In: Thapman PK (ed) Organic agriculture. Peckay Tree Crops Develpoment Foundation, Cochin, pp 78–100 Stephenson J (1930) The oligochaeta. Clarendon Press, Oxford

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Anatomy of Earthworms

2.1 Body Structure 2.1.1 Earthworm Body The body of earthworm is muscular tubular (elongated) with numerous external rings which more or less internally correspond segments. On internal and external rings body segments are organized over body system.

2.1.1.1 External Characters All earthworm species have long elongated tubular body. The tubular body of earthworm is generally circular in section with annuli, which is formed with superficial grooves. This represents typical vermiform body. The close examination shows that shape of body of earthworms is nearly circular squarish or trapezoidal, if cut into section, vary in different species. In some species like an arboreal Perionyx spp., their body is dorsoventrally flattened, which is in most live forms of other species. Body color also varies in different species due to pigments and ranges from typical/rich brown to various hues of red gray and purple. In some, there is some luminence too. In live earthworms, color can help in differentiating habitat, viz., burrowing forms have light pigmentation, while top soil dwellers have darker pigmentation. Externally the earthworm body has series of circular depressions or furrows called segments or metamers. These tally with internal segmentations too and their numbers, as well, in relation to internal organs which are characteristic in different species. Mouth is crescentic in shape and lies on the ventral side of a first segment, i.e., peristomium. Shape and placement of prostomium is also characteristic in different species. This first metamere with prostomium is called buccal segment as it does not correspond to internal segmentation. All along metameric segments or mid region are attached chitinous hook like structures called chaetae or setae. These are © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_2

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retractile and offer hold in locomotion. Their number, placement, shape, arrangement pattern, and descriptions in relation to characteristic features (the pores) are taxonomic character. There are numerous pores opening out externally. These have been named with functions and location on body and are of taxonomic importance. Most of these are not visible without use of magnifying glass. Various pores are: (1) Dorsal pores located within interseg mental furrows; (2) Nephridial pores which are minute and scattered irregularly over body surface.

2.1.1.2 Digestive System The digestive system comprises a tubular alimentary canal extending from mouth to anus. Upon their dissection various parts of the digestive system can easily be differentiated, namely buccal chamber/cavity, pharynx, esophagus, crop, gizzard, intestine, and rectum. Mouth is at extreme anterior end (first segment) and opens into a short buccal chamber. At tip of mouth a bulbous lip is attached and is called prostomium whose size, shape, and location vary between different species. So, it is a taxonomic character. In some species like common Indian Earthworm, Metaphire posthuma buccal cavity is continuously protruded out to pick food particles. Lining of prostomium and buccal cavity is very receptive as it contains receptor cells. Due to these earthworms can discriminate and show preference to different kinds of food items. Buccal cavity joins a muscular pear-shaped structure known as pharynx. In some species, pharynx can also be turned inside out (evaginated) to accept food particles with help of prostomium. Pharynx is pulled back (evaginated) and food is pushed in alimentary canal. In some species within pharynx, there are pharyngeal glands or salivary glands which produce mucin for lubrication of food. The secretion of mucin perhaps helps in formation of stable soil aggregates excreted as “castings” (feces). It is also believed that mucin also promotes bacterial growth and rate of humification in soil, which is a very important process for maintenance of soil fertility. Pharyngeal glands also produce proteolytic enzymes which convert ingested protein materials to simple absorbable forms for plants, majority of these pass out or excreted as casting. This in turn increases plant absorbable nitrogen content of soil so as the nutrient in available form is present in the rhizosphere for its absorption by plant roots. Pharynx joins a tubular structure called esophagus in which calciferous glands open. These secrete calcium and carbon dioxide. Calcium probably neutralizes contents of alimentary canal making excreted cast alkaline, thereby helps in reduction of acidity of soil (i.e., cast and with use of vermicompost). Posterior end of esophagus is thin-walled in some species it acts as storage organ. This joins gizzard called as crop. Gizzard is a muscular structure which functions as grinding of food substrate. This is with the help of grit particles within food and with internal cuticular epithelium or lining within gizzard, besides muscular contractions, etc. the ingested food is grinded into fine particles. Some species of worms have two gizzards in sequence and others have up to ten gizzards that appear as a beaded muscular tube. These also comprise taxonomic characters. However, some aquatic species do not have crop and gizzard. Gizzard follows tubular canal which has sphincters valves at both end and internally has epithelial folds having

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glandular and nonciliated cells. This portion of alimentary canal was named by Kirtisin ghe in 1939 as stomach. In stomach proteolytic enzymes are secreted which digest proteins. In some species, namely common Indian earthworm (Metaphire spp.) and in Eutyphoeus spp. have calciferous glands also. These show structural variation between species. Many globally acknowledged zoologists work is documented in literature as Charles Darwin opined that functionally secretions of calciferous gland are to neutralize humic acid of decaying leaves that earthworm consume. Robertson disagreed and opined that the function is to excrete extra calcium. While S.  Stephenson, Bani Prasad, and K.N.  Bahl gave structures of these calciferous glands between 1930–1950. Since then, however, not much has been studied despite curriculum studies of earthworm all over country and rather world over. Stomach follows or joins a thin-walled tubular structure called intestine that ends at body end the anus. The digestion and absorption of ingested food take place in intestine. Structurally intestine has three regions, namely: (i) Pre-typhlosolar region which has vascular internal folds. In the region after few segments, there are conical outgrowths called intestinal caeca. These, according to Chen and Puh, structurally, caecae have glandular epithelial cell and secrete amylatic enzyme, so these are digestive glands. (ii) Typhlosolar region is the middle part of intestine and structurally is differentiable with medium longitudinal folds inside the intestine called typhlosole. This structure shows difference in content to its size, shape, and blood supply. In common Indian earthworm, it is more or less rudimentary, while in common European earthworm, Lumbricus spp., typhlosole is very well developed and contains chloragogen cells to increase food absorption with increased surface area. Chloragogen cells are either excretory or function as storage cells of nutriments in the absence of liver in earthworms. (iii) Last part of intestine is known as rectum and contains feces as rounded pellets which are excreted through anus. The excreted feces are known as castings or casts. Collective mass of casts from earthworm culture or decomposable organic wastes are generally called “vermicompost.” However, technically cast and vermicompost are differentiable, former being excrement from soil and later being casts from decomposed organic matter. Physiology of digestion in earthworms in many respects is comparable to functions in higher animals. Depending upon feeding habits, dissimilar species have different enzymes for digestion. In most species, enzyme amylase is secreted that digests starch, thereby C/N ratio of substrate is reduced after passing through intestine, the material is converted into readily assimilable form for plants. Other species may have enzymes like diastase which converts starch into sugar. Some have glycogen hydrolising ferment, lipase (for digesting fats), invertase (acting of cane-sugar) and oxidizing ferment-catalase. In some earthworms evidence of presence of cellulase and chitinase have been reported, but are suggested to have been produced by symbiotic bacteria and blood and coelomic fluid to different parts of body.

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2.1.1.3 Body Cavity or Coelom Body structure in worms is comparable to a tube and tube inside has digestive organs or body organs. In between these two is a body cavity called coelom, which is generally filled with a milky fluid called coelomic fluid. The coelom is enclosed on outer side with inner peritoneal lining of body wall. It is covered with peritoneal lining of alimentary canal in the inner side. Coelom is partially or completely divided by muscular partitions called septa which stretch along inter segmental furrows to alimentary canal or organs. Disposition, thickness, position number(s), and attachments to organs are characteristic features of different species. Coelomic septa have apertures with sphincters to control fluid movement. The function of these apertures is to regulate flow of coelomic fluid to different segments of body for making these turgid which helps in locomotion. Coelomic fluid mainly comprises colorless plasma fluid. In this, various types of corpuscles float and it vary in different species. Commonly found corpuscles are amoebocytes, granulocytes, and leucocytes. Amoebocytes are defense cells against parasites and pathogenic cells which are devoured. Granulocytes contain granules that are believed by many scientists as nutritive in function and carry digested granules to various tissues. Liebmann (1942) opined that leucocytes are also modified amoebocytes, so are expected to have some defense function. Biochemically, coelomic fluid is slightly alkaline (pH 7.9) and is at higher osmotic pressure than surrounding water in substrate. On movement of worm, the fluid appears moving forward and backward. It is still not known whether it is only in appearance due to turgidity in segments or actually in process. However, exudation through skin pores does take place. This is believed to protect worm from bacteria and similar pathogens. The fluid exudation also keeps body surface damp and is also believed to help in respiration besides excretory in function. This is also opined to help in formation of stable aggregate in casts, thus stimulates growth of certain bacteria that help in humification of organic matter present in soils. Worldwide common prank in children is sprinkling of common salt over live earthworm to see killing violent contractions and ultimate of worm. This is due to ex-­ osmosis of coelomic exudations of fluids which further cause violent contractions leading to ultimate death. In Squirter worm, Dielymogaster sylvaticus, body fluids are ejected to a height of 30 cm to avoid predator. 2.1.1.4 Body Wall The body wall of earthworm is complex as in other animals. Complete description of its body wall would necessitate background of animal morphology. Therefore, to simplify only brief description is being dealt with. Technically, body wall comprises five layers. These are (i) Cuticle comprising of two fine transparent layers. The color hues on earthworm body are due to stridulations on these layers. (ii) Epidermis layer is below cuticle layer. Epidermis comprises four types of cells, viz. glandular mucus, albumin, supporting basal and receptor cells. These serve various functions.

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(iii) Muscular layer lies below epidermal layer. Muscular layer has two types of muscles, in layers. These are outer ones (circular) and inner ones (longitudinal). Follicles are present within epidermis, which secrete chitinous setae that protrude outside body. These are placed in single line around periphery of each segment. Structurally setae are fine microscopic, needle like structure. Setae, being chitinous and supported with muscles chiefly serve functions of locomotions. In some species these comprise important taxonomic characters.

2.1.1.5 Locomotion Setae of earthworms are chiefly locomotory purpose organs. Some setae also play role in copulation. Locomotion in earthworms involves set of synchronized activities from circular and longitudinal muscles, the setae, the septa, and body cavity. In soil when space is available, worm will elongate extending its interior end into the space, grip the surface with setae, expand sideways by contracting longitudinal muscles, and finally pushing aside soil particles from its burrow. Thus by burrowing, burrow formation is affected. If space is not available, viz. there is a non-­ burrowing object or hardened soil, worm will circumvent such obstacle. On finding palatable material, worm will swallow by gripping it with everted pharynx and swallowing with retraction of pharynx. Due to this activity, many refer locomotion and burrowing as ‘worms cats its way’. Occasionally even in language, process is referred as proverb, viz. eating like a worm or eating its way through. Respiration: Respiration in earthworms is simple but very efficient. Terrestrial earthworms do not have any specialized organs for respiration; however, some aquatic worms have gill like organs. In the majority of worm species, respiration is through skin, i.e., body wall having plentiful blood supply. Body wall is kept moist by mucus glands, oozing coelomic fluids through dorsal pores, nephridial excretions, and also the ground moisture. The exchange of carbon dioxide with oxygen is done through permeable body wall epidermis and blood capillary network having respiratory pigment, the hemoglobin which transports exchanged and dissolved oxygen to different parts through blood vessels. This oxygenation or respiration occurs both at low oxygen pressure, as well as at high pressure from air. But the efficient respiration takes place when skin is moist. The earthworms can live under low levels of oxygen for 6–30 h. That is why the earthworms survive when they are buried in soil. 2.1.1.6 Excretion Excretion processes are brought about by various developed body functions. Main organs for excretion are tubular structures called Nephridia, present in different body segments within coelom. Their numbers, shapes, sizes, and location considerably vary between species and in some these help in identification. In most species, broadly structure of nephridia comprises a funnel shaped structure with ciliated cells called nephrostome which lies in the segment preceding to one occupying main body of nephridia. Nephrostome or nephridiostome is linked to a small tube

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which joins the convoluted mass. The body of nephridia remains attached with tissues. According to excretory action: outside (exonephric) or inside (enteronephric), nephridia are named. Also, according to location within body, nephridia are named, viz. septal (on septum), integumentary (on integument), and pharyngeal (on pharynx). Nephridia also differ in sizes, viz. large (meganephridia) and small (micronephridia). The excretory functions begin with nitrogenous wastes from different organs and systems that are diffused in coelomic fluid, getting into nephrostomes. The ciliated funnel of nephrostome allows only preferred entry of materials. The fluids then pass through canals of nephridia which with selective absorption extract water and other useful materials, but allows passage of only nitrogenous wastes. These materials like urea, ammonia, and amino acids, besides some comprise other materials like creatinine. These pass out through nephridiopores. In nephridia that are devoid of nephrostomes, wastes are directly absorbed by body of nephridia and passed out of nephridiopores or are transferred into gut. Enteronephric nephridia are perhaps adaptive features for preservation of water within worm body. Exonephric nephridia excrete wastes to exterior through nephridiopores as urine. Urine binds soil particles and forms stable aggregates of soil, stimulating microbial growth for humification or organic matter. Several other excretory mechanisms are working in earthworms. Certain unique cells called chloragogen cells present in the coelomic epithelium of intestines are important in removal of excretory materials from blood. These acts like a mobile liver to maintain required levels of certain substances in blood and coelomic fluid. In Eutyphoeus spp. even hepatopancreatic glands have been reported. Other excretory cells are uric or bactericidal cells which also function like amoebocytes. Therefore, nephridia remain as most important excretory organs, functioning like kidney of higher vertebrates, performing functions of excretion, filtration, re-­ absorption and chemical transformation.

2.1.1.7 Circulatory System Blood of earthworms is peculiar to its life activities. The blood plasma or fluid of worms is red colored because of dissolved hemoglobin (the transporter and absorber of oxygen) while corpuscles suspended in the fluid are colorless and are nucleated. The hemoglobin gets saturated with oxygen to as high as 95% (in form of oxyhemoglobin) and gets unloaded with transfer of oxygen to different organs in blood circulation process, e.g., in respiratory physiological process that continues even at lower (generally above 19  mm) oxygen pressure. Thus, earthworm hemoglobin functions efficiently both at saturation point, as well at low environmental oxygen levels. These qualities surpass even so advanced creatures like Homo sapiens, the man, whose hemoglobin at a level below oxygen saturation point, would “drown in oxygen,” i.e., succumb. Further man cannot easily survive in prolonged low or high levels of oxygen; however, earthworms can survive. The blood vessel system in earthworms is complex as in higher animals. It has been divided into three parts, viz. in the region of intestine, in first 13 body segments, and circulation course of blood. The circulatory system of earthworm comprises three principal blood vessels, namely dorsal vessel, sub-neural vessel, and ventral vessel. The dorsal vessel runs

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along the upper midline of the gut and it is the main blood collecting vessel. Blood is moved in forward directions by contractile actions of dorsal vessel. Lying close to nerve chord is sub-neural vessel. Some earthworm species do not have sub-neural vessel, while most (except Megascolecidae species) have two such vessels. Its branches collect blood from anterior tissues and organs and return it to dorsal vessels by dorso-sub-neural vessel which run in the septa of each segment. The ventral vessel supplies blood to organs, including skin. In this vessel, blood flows anteriorly to posteriorly. By neural and sub-neural vessels, blood is collected and passed on to dorsal vessel. Pumping of most of the blood from dorsal vessel is into ventral vessel by several (3, 4 or 5 nos.) pairs muscular hearts with valves surrounding esophagus. The flow of blood is unidirectional. The blood this way distributes digested nutrients from food to various regions of body and collect waste materials which pass out to nephridias, coelomic fluid, and to skin. From capillaries of skin, hemoglobin carries the absorbed oxygen to various other tissues.

2.1.1.8 Nervous System The nervous system of earthworms consists of brain which is in form of fused ganglia lying dorsal to pharynx and it is called as supra-pharyngeal ganglia. From their brain, a pair of circumpharyngeal connective arises, which encircles pharynx and ventrally joins with a pair of sub-pharyngeal ganglia. From ganglia, starts nerve chord that runs up to posterior end. On nerve chord are swellings, i.e., ganglion which give off nerves to various structures within segments. These nerves have both sensory and motor fibers. Sensory fibers provide stimuli to nerve chord and stimulus is transferred to motor fiber going to muscles affecting them contract. In the epidermis of earthworms, at places, localized nerve cells are present in the form of receptors. These are of different kinds. Epidermal receptors are sensitive to touch and also perceive thermal and chemical stimuli. Buccal receptors are found in the epithelium of buccal cavity. These receptors can perhaps smell and taste food. The earthworms are able to differentiate their food items due to these receptors. Photoreceptors are mainly concentrated on prostomium and first body segment. Because of these, the earthworms negatively respond to strong lights and somewhat positively to weak lights. These explain process of retraction of worms during bright days and their emergence during nights. However, these responses vary in different species. There are some earthworm species that emerge only during night like African Night Crawlers, the Eudrilus spp. Interestingly, it is reported that in Canada, collection of Lumbricus terrestris during night (through Flash lights) is widely done. So, collected earthworms are exported to USA for use as fish baits. It is time that developing countries start paying more attention to such aspects. 2.1.1.9 Reproductive System Earthworms are hermaphrodite having ovaries and testes in same individual. Mostly cross fertilization occurs in earthworms due to relative positions of male and female genital apertures. Earthworms are protandrous, i.e., male sex cells ripen much earlier than female cells. Therefore, self-fertilization is prevented.

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(i) The male sex organs consist of two bag like sacs comprising testes that produce spermatogonia (immature sex cells). Spermatogonia are shed in testes sacs and transfer to seminal vesicles where these undergo further maturation and form spermatozoa (mature male reproductive cells), pass through funnel shaped structure to vas deferens (tube-like structure), and finally are discharged to exterior through male genital pores located on ventral side. Position of male genital pores varies in different species, so the character is of taxonomic importance. (ii) The female sex organs consist of ovaries, in which egg cells are produced. Ovarian funnel is located below ovaries that lead to tubular oviduct opening to exterior through female genital pores located on ventral side. Besides, male and female organs, there are paired organs called spermatheca in which sperms flowing from other partners are stored and are nourished by some fluids.

2.1.1.10 Reproduction and Cocoon Formation Fertilization as a rule in earthworms is cross fertilization, i.e., eggs of one individual are fertilized by sperms of other individual. For this exchange process copulation takes place in which two individuals lie opposed to each in head to tail position with spermathecal pores, closely addressed to each other pores. Each copulating individual move sequentially till all sperms are discharged into spermathecae. This process is also referred by some as charging of spermathecae. Copulatory activities differ in some species as in some earthworm species, the male sex pores are raised to form papillae with a cup like attachment. The prostatic duct (sperm duct) like structure is evaginated to form a penial structure that is inserted for direct transmission of sperms. Separation of copulating individuals succeed changes in clitellum which gradually gets covered with a mucilage. This process follows release of ovum by individuals within mucilage cover and comprises the stage when fertilization takes place with simultaneous release of sperms. In some species, fertilization within mucilage cover occurs when copulating individuals retract backward from the albuminous mucilage rings. In some, it is after separation. However, fertilization from single individual is also reported in some species, viz. Dichogaster bolaui. After fertilization, the cocoon or the egg capsule is formed from clitellar gland which is having three layers and is believed to be made from some kind of chitinous material and also has proteins. This is actually formed in most species when individual worm retracts out from the albuminous mucilage ring over its clitellum. This contains albumen and outer covering gradually hardens on exposure to air. Shape of cocoon: The shape of cocoons in general is ovoid. Freshly laid cocoons are whitish or dull white, soft, and jelly like. In most species, cocoons are laid on surface of substrate when temperature (for embryo development) and moisture are favorable. Season: In most parts of India, viz. in common earthworm, Metaphire posthuma, cocoons are laid from April to October with peaks between August and October months. In Drawida bolaui, peak cocoon laying 5000/m2 has been reported during mid-September with earthworm population of 1150/m2 individuals. All these

2.1  Body Structure

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indicate reproductive activity, i.e., survival of juveniles in summers. The vermiculturists/farmers should periodically monitor these earthworms in their culture troughs or beds. The information so generated will enable vermiculturist maintain profitable culture and eventually better compost productions from material under use.

2.1.2 Shape, Size, and Color of Cocoons Color: The color variations vary from yellowish brownish to greenish brown. However, in some species, these are milky white like pearls. Shape and size: The shape of cocoons is mostly coriander seed shaped with both tapering ends. But these vary and in Criodrilus spp. ornamentations on spindle shaped structures (are reported by Prof. B.K. Senapati) are long (1.5–7 cm) corresponding to length of clitellum. Size of cocoons also varies between species. Professors B.K. Senapati and S.K. Sahu have studied in detail on 15 temperate and tropical species, respectively, range as follows: Temperate species: have dry weight (mg) 0.86–12.0 mg; diameter 1.3–3.7 mm and length 2.0–6.9 mm. In most commonly used species, Eisenia foetida, dry weight is 3.7 mg; diameter 2.9 mm and length 6.0 mm. Tropical species: have dry weight 0.65–32.60  mg; diameter 1.0–9.0  mm and length 2.0–15.0  mm. Cocoons of world’s largest earthworm of Australia, Megascolides australis has diameter of 20 mm and length of 75 mm. It contains single embryo which on emergence measures nearly 30 cm s, i.e., 1 ft. Temperature and moisture level for cocoon production: The production of cocoons and its survival is important for further progeny. These are dependent upon several factors. In general, optimal conditions are at substrate temperature range between 15 and 25 °C (depending upon species, design of the vermiculture container, and weather control measures like shade), with 20–40% moisture in substrate, i.e., 60–100% air humidity, ionic conductivity below 3 m mhos/cm darkened environment. Feed substrate preparation is essential step and should not have any contamination with lethally toxic chemicals. Survival rate: In each cocoon, number of eggs may range high. However, survival is only in one or two or three. Production of cocoons with favorable conditions is throughout the year. During colder months, less number is produced than in warmer months, so cannot be generalized for reproduction rates (cocoon production as indicator) of various species in different regions. Prof. B.K.  Senapati and S.K. Sahu have reported annual cocoon production per adult/year in 15 temperate and 15 tropical species. These corresponding values range between 8.00 and 92.00. and 1.30 and 46.59per adult/year, respectively. The earthworm species, E. foetida have an average of 17 cocoon production per adult/year. When two individuals mate at a time and release their individual cocoons, then cocoon production is actually double the number. Incubation period: Incubation period ranges 3–30 weeks in temperate species and 3–8  weeks in tropical species. The incubation period of two common earthworms species widely used in Vermiculture, namely Eisenia foetida is 3–4 weeks

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and Eudrilus eugeniae is 2–3 weeks, respectively. However, their further development also depends upon temperature, moisture, and substrate conditions. On an average, young ones grow to maturity in 2–13 months. In vermiculture, preference is given to those species which have higher rate of reproduction, quick maturity, and faster development, besides other parameters. The African species which are widely used for vermiculture have characters, viz. freshly emerged individuals have rapid growth and attain reproductive stage (develop, clitellum) within 6 weeks and cocoon laying continues for 3–6  months when gradually number decreases. The earthworms then can be harvested for other purposes. Environmental conditions and soil pH: Under natural conditions, reproductive potential and other activities of earthworms depend upon some important factors, viz. environmental conditions and soil pH. Most earthworms prefer neutral soils. Eisenia foetida, common sewage worm, prefers alkaline soils and some others prefer or tolerate slightly acidic soils. Moisture conditions: Moisture conditions of soil as well that of worm body influence its distribution, viz. vertical distribution to soil surface when availability of leaf litter is more. So better growth and soil conditioning is expected unless humus is available in lower reaches (for example, in pits). Under decreased moisture conditions, worms go in deeper layers and may undergo diapause. Temperature: The temperature has also direct bearings to reproduction and distribution, etc., as affects various activities like metabolism, respiration, growth, reproduction, production, and hatching of cocoons. Temperature tolerance range is different for various species. Extremes of temperature range limit tolerances and activities. Types of soils: Types of soils also determines the total biomass of worms to be supported. In general, light and medium loam soils have more worms than heavier clays and alluvial soils. Kind of food: The kind and amount of food influences their type, number growth, and fecundity. Other factors related to worm reproduction and distribution are feed and its availability. Earthworms produce more cocoons when these are fed on decaying organic matter or on nitrogen-rich diets. Among vegetable matter, leaf litter is most preferred. Many species are reported to possess capability to discriminate leaf litter according to shape, mineral, alkaloid, and protein contents. With careful observations, it is simple to make out suitability of leaf litter or other organic material for earthworm propagation.

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Earthworms, Their Species, and Biological Features

In underdeveloped countries, green revolution has resulted in boosting the production due to intensive agriculture. Although it has resulted in good harvests and productivity by reaping three crops annually with good irrigation facilities, there was no thought about its adverse impact in the long run on the soil conditions and the environment. With the extensive use of chemical fertilizer without organic manures and improper irrigation, productivity of the soil is getting reduced considerably. The permanent and cheapest solution to overcome the dangerous effects of modernized agriculture is to develop a farming system which is economically productive and long-lasting in sustainable farming or natural farming by simple and inexpensive practices like vermi-biotechnology. Therefore, the old agricultural systems, viz., biological, organic, ecological, regenerative, natural, biodynamic, and low input agriculture are reconsidered for their sustainability. Sustainable agriculture is a process of learning new advanced methods developed by both farmers and the farm scientists and is also learning from the indigenous traditional knowledge practices of the farmers and implementing what were good in them and also relevant in present times. Vermiculture was practiced by traditional and ancient farmers with enormous benefits for them and their farmlands. Therefore, there is a need to revive this traditional concept through modern scientific knowledge. “Sir Charles Darwin” called the earthworms as “farmer’s friends.” There is great wisdom in this statement of the great visionary scientist who advocated to use the earthworms, the nature’s gift in farm production (Fig 3.1). Vermicompost is rich in microbial diversity and plant-available nutrients; improves moisture-holding capacity of soils, thus reducing water for irrigation; improves physical, biological, and chemical properties of soil; increases soil porosity and softness, thus requiring minimum tillage. Earthworms have over 600 million years of experience in waste and land management, soil improvement, and farm production. “Sir Charles Darwin” called them as

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_3

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Fig. 3.1 Earthworms in soil

the unheralded soldiers of mankind and farmer’s friend working day and night under the soil.

Earthworms play a significant role as ecosystem engineers in various habitats and offer essential ecosystem functions and services (Adhikary 2012). The capacity of earthworms to provide these ecosystem functions is likely influenced by factors like their abundance, biomass, and ecological classification (Arancon et al. 2002). Consequently, it is crucial to comprehend global trends in community metrics related to earthworms to anticipate how modifications in their communities might impact ecosystem operations. Small-scale field investigations have revealed that soil characteristics, including pH and soil carbon content, have an impact on the diversity of earthworm populations. For instance, lower pH levels limit earthworm diversity by decreasing the availability of calcium, whereas soil carbon provides resources that support the diversity and population sizes of earthworms. In addition to various interacting soil attributes, numerous other factors, such as climate conditions and habitat coverage, can also influence the diversity of earthworms (Arancon et  al. 2008). The earthworm diversity in tropical regions could be notably high, mainly due to a prevalence of unique species. Nonetheless, it is important to note that this elevated regional diversity might not necessarily be reflected in local-scale measurements. Conversely, in temperate regions, local diversity may be greater, but it might encompass fewer species that are exclusive to that area. Various studies showed that although plant diversity increases with potential evapotranspiration (PET), earthworm diversity tend to decrease with increasing PET. In addition, soil properties, which are typically not included in models of aboveground diversity, can play a role in determining earthworm communities (Arancon et al. 2007; Azarmi et al. 2008). For instance, litter availability and soil nutrient content are important regulators of earthworm diversity. Moreover, tropical areas which have higher decomposition rates tend to have fewer soil organic resources and lower levels of local earthworm diversity (Fig. 3.2b). This lower diversity is often characterized by the prevalence of endogenic species, which possess specialized digestive systems enabling them to thrive on low-quality soil organic matter. Conversely, temperate regions situated at mid to high latitudes, particularly those that were once glaciated,

3  Earthworms, Their Species, and Biological Features

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Fig. 3.2  A recent study on global distribution of earthworm species. (a) Black dots represent the center of a “study” used in at least one of the three models (species richness, total abundance, and total biomass). The size of the dot corresponds to the number of sites within the study. Opaqueness is for visualization purposes only. The globally predicted values of (b) species richness (within site), (c) total abundance, and (d) total biomass. Yellow indicates high diversity; dark green, low diversity. Light green areas are habitat cover categories that lacked samples. (Source: Adapted from Phillips et al. 2019)

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Fig. 3.2 (continued)

are likely to have been recolonized by earthworm species boasting extensive dispersal abilities and wide geographic ranges, facilitated in part by human-mediated dispersal.

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In temperate regions, local communities can exhibit substantial diversity, but many of these species tend to have wide distributions, leading to a relatively lower level of regional diversity compared to local diversity. Conversely, in tropical regions where glaciation did not occur, the situation may be reversed. Certain specific locations within the tropics might harbor highly unique species, but these species tend to have limited distribution ranges. When researchers computed the number of distinct species within latitudinal zones that had an equal number of sampling sites (effectively considering sampling effort), they observed the emergence of a latitudinal diversity gradient at the regional level. In the tropics, regional species richness was greater than in temperate regions, despite the fact that local diversity in the tropics was relatively low. However, the underlying data suggests that endemism of earthworms and biodiversity within the tropics may be considerably higher than within the well-sampled temperate region (Canellas et al. 2002). Therefore, it is likely that the tropics harbor more species overall.

3.1 Earthworm Species 3.1.1 Redhead Worm See Fig. 3.3.

Fig. 3.3  Redhead worm Scientific Name: Lumbricus rubellus Family: Lumbricidae

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This earthworm displays a reddish-purple hue at one of its ends, which has led to its common moniker, the “redhead worm.” It typically reaches a medium size, ranging from 4 to 5 inches when fully mature. One distinctive feature used for identification is its occasional tendency to flatten its tail, creating a paddle-like shape. Originally native to Western Europe, this worm has now proliferated extensively throughout North and South America, establishing itself as an invasive species in these regions.

3.1.2 Common Earthworm See Fig. 3.4. This earthworm species, often referred to as the “dew worm” or “lob worm,” originates from Western Europe. However, due to the transportation of plants and worms for fishing bait purposes, it has now become widely distributed across North and South America, Asia, Africa, and Oceania. Regrettably, it is classified as an invasive species with a diet that includes consuming leaf piles on the soil’s surface as well as the upper soil layers. These worms possess robust muscles that enable rapid movement, serving as an effective defense against predators like foxes, shrews, and birds. They exhibit a darker coloration at one end, characterized by a red-brown pigmentation. Their presence is most noticeable during wet weather, while during dry periods, they tend to burrow into the top layers of the soil to seek protection from both extreme heat and potential predators.

Fig. 3.4  Common earthworm Scientific Name: Lumbricus terrestris Family: Lumbricidae

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3.1.3 Green Worm See Fig. 3.5. This particular endogenic earthworm variety stands as the most prevalent earthworm species within the UK, constituting approximately 34% of all identified earthworms in the region. It is colloquially known as the “green worm” due to the presence of bilin pigment in some individuals, which imparts a greenish hue. However, the majority of these worms actually exhibit pink morphs, so encountering a “green” worm that is, in reality, pink is more likely. The truly green variants are more frequently observed in grassland environments, although scientists have not yet clarified the reasons behind this variation. The pink morphs of these worms are distinguished by a faint yellowish ring near their upper end, and upon close examination of the saddle’s underside, one might notice the presence of three disc-­ like structures resembling suckers. When fully mature, these worms typically measure around 2 inches in length.

Fig. 3.5  Green worm Scientific Name: Allolobophora chlorotica Family: Lumbricidae

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3.1.4 European Night Crawler See Fig. 3.6. This particular worm is also recognized by names such as the “greenhouse worm” or the “compost worm.” This nomenclature stems from its increasing popularity in compost production, although it remains predominantly utilized as bait for fishing. When these worms have not consumed food, they typically exhibit a pinkish tint, while after feeding, their coloration tends to shift toward a more bluish-gray hue. They are characterized by prominent bands and numerous stripes along their bodies, with tails that appear paler than the rest of their form. These worms are commonly encountered in environments marked by moisture or dampness, including compost heaps, manure piles, accumulations of decomposing leaves or other organic garden materials, and bark.

3.1.5 Brandling Worm See Fig. 3.7. These epigean worms are dwellers of the surface and are seldom found within the layers of soil. They primarily inhabit and feed on decomposing plant matter,

Fig. 3.6  European night crawler Scientific Name: Eisenia hortensis Family: Lumbricidae

manure, and compost. Like other epigean worms, the brandling worm is quite agile

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Fig. 3.7  Brandling worm Scientific Name: Eisenia fetida Family: Lumbricidae

in its movements, which aids in evading potential predators. Each segment of its body features hair-like structures resembling bristles that enable it to grip surfaces, facilitating both forward and backward motion and enhancing its overall maneuverability. The term “Fetida” roughly translates to “foul-smelling,” alluding to the noxious liquid the worm secretes when handled. This secretion is believed to serve as a defense mechanism against potential threats. Additionally, this worm goes by the common names “tiger worm” and “trout worm.” It is indigenous to Europe but has been introduced to every continent worldwide, with the sole exception of Antarctica.

3.1.6 Giant Gippsland Earthworm See Fig. 3.8. This worm is indigenous to Australia and stands out as one of the largest earthworm species globally, typically measuring between 30 and 40 inches in length. Its front segment, encompassing the head, displays a dark purple coloration, while the rest of its body appears pink-gray. These worms are typically found in deep, moist soils, often near riverbanks and streams. They construct intricate burrows, usually reaching depths of around 2 feet, but they are capable of burrowing as deep as 5 feet into the soil. Their diet consists of roots and other organic material within the soil, although they occasionally extend their heads above the soil surface in search of

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Fig. 3.8 Giant gippsland earthworm Scientific Name: Megascolides australis Family: Megascolecidae

alternative food sources. Unfortunately, this worm faces a declining population, largely attributed to soil cultivation and modern farming practices. Additionally, it exhibits a low reproductive rate and slow growth, further impeding its capacity to increase its population size.

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3.1.7 Washington Giant Earthworm See Fig. 3.9. This elusive worm was initially identified near Washington in 1897 but had seemingly vanished by the 1980s, as no sightings of this species were reported for a significant period. However, in 2010, two specimens were rediscovered, prompting a revision of its conservation status. Presently, the worm is categorized as having a vulnerable conservation status, although environmental organizations have advocated for its recognition as an endangered species. This worm is known for its burrowing behavior, often reaching depths of approximately 15 feet, with the deepest burrows occurring during the summer to avoid drought conditions. While it is believed that this worm can attain lengths exceeding 3 feet, recent discoveries have shown that they are typically around half the anticipated size. Notably, it lacks pigmentation, appearing either white, pale pink, or translucent in coloration.

3.1.8 Gray Worm See Fig. 3.10.

Fig. 3.9 Washington giant earthworm Scientific Name: Driloleirus americanus Family: Megascolecidae

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Fig. 3.10  Gray worm Scientific Name: Aporrectodea caliginosa Family: Lumbricidae

This worm is commonly found in the UK, where it lives in the top layers of soil in non-permanent burrows. It typically measures between 2 and 3 inches long and can be identified by its distinctive coloring. At its front-end, the worm is banded into three segments, which are pink, gray, and brown.

3.1.9 Composting Worm See Fig. 3.11. This tropical worm is believed to have its origins in the Himalayan mountains. Today, it is extensively cultivated on a commercial scale for its role in composting. Its remarkable capacity to rapidly generate worm castings, which play a pivotal role in expediting the decomposition of compost, has garnered increased attention in the North American market. This surge in interest aligns with the growing popularity and widespread adoption of home composting practices. The worm thrives particularly well in moist environments.

3.1.10 African Night Crawler See Fig. 3.12. Originally hailing from West Africa, this worm has expanded its presence across tropical and warm regions characterized by temperatures consistently ranging from 75 to 85 °F. This worm is straightforward, as its entire body boasts a dark purple hue with a noticeable glossy sheen. Notably, its posterior end tapers down to a fine point. What distinguishes this worm is its remarkable proficiency in expediting the decomposition of composting materials.

3.1  Earthworm Species

Fig. 3.11  Composting worm Scientific Name: Perionyx excavatus Family: Megascolecidae

Fig. 3.12  African night crawler Scientific Name: Eudrilus eugeniae Family: Eudrilidae

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3.2 Biological Features of Earthworm An earthworm is a segmented worm; a terrestrial invertebrate belonging to the phylum Annelida. They are the common inhabitants of moist soil and feed on organic matter.

3.3 The Morphology and Anatomy of the Earthworm Are Discussed Below The diagram given below represents the morphological features of an earthworm (Fig. 3.13). Earthworms possess a cylindrical, tube-like body with a reddish-brown coloration and distinct segmentation. Their body is composed of small segments, with the dorsal side featuring a noticeable dark line of blood vessels, and the ventral side housing the genital openings. The anterior end of the earthworm is distinguished by the presence of the mouth and the prostomium, an organ that aids in burrowing. In mature earthworms, segments 14–16 are marked by the presence of a glandular tissue known as the clitellum, which serves as a distinguishing feature between the mouth and tail ends. The body can be divided into three segments relative to the clitellum: the preclitellar, clitellar, and postclitellar regions. Earthworms exhibit hermaphroditism, meaning they possess both male and female reproductive organs. Specifically, segments 5–9 house four pairs of spermathecal apertures. The female genital pore is located on the 14th segment, while a pair of male genital pores can be found on the 18th segment. To aid in movement, the earthworm’s body is equipped with S-shaped setae, which are present in every segment except the first and last segments, as well as in the clitellum region.

Fig. 3.13  Anatomy of the earthworm

3.3  The Morphology and Anatomy of the Earthworm Are Discussed Below

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3.3.1 Anatomy of Earthworm On the external surface, the earthworm’s body is coated with a thin, non-cellular cuticle. Below this cuticle lies the epidermis, which is succeeded by two layers of muscles, and finally, the coelomic epithelium forms the innermost layer. This epithelium comprises a single layer of glandular columnar cells.

3.3.2 Digestive System The earthworm’s digestive system is a lengthy tube that spans from the first to the final segment of its body. Earthworms primarily consume leaves and decaying organic material, which becomes mixed with the soil. Due to their unique diet, the structure and secretions of their alimentary canal differ from those of other organisms. The alimentary canal commences at the mouth, spanning the initial 1–3 segments, and then proceeds through the pharynx, esophagus (5–7 segments), muscular gizzards (8–9 segments), stomach (9–14 segments), intestines, and eventually terminates at the anus. As food particles traverse through these various compartments of the alimentary canal, they undergo gradual digestion. The muscular gizzards play a crucial role in grinding soil particles and other materials, while in the stomach, the calciferous glands neutralize the humic acid found in humus. To enhance absorption, the intestine features a structure known as the typhlosole, which extends from segments 26 to 35 and increases the surface area available for nutrient absorption.

3.3.3 Circulatory System Earthworms possess a closed circulatory system, which includes components such as a heart, blood vessels, and capillaries. Blood glands located in segments 4–6 play a vital role in the production of blood cells and hemoglobin.

3.3.4 Respiratory System Earthworms lack a well-developed structure for respiration. They respire through their moist skin by diffusion.

3.3.5 Excretory System The nephridium comprises coiled tubules responsible for regulating the volume and composition of body fluids, serving as the excretory organ in earthworms. Nephridia are organized into three types, namely septal nephridia (found in segments 15 to the last segment), integumentary nephridia (from segment 3 to the last segment), and

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pharyngeal nephridia (located in segments 4–6). These nephridia are connected to a funnel that facilitates the removal of waste products and excess fluids, ultimately expelling them through the digestive tube.

3.3.6 Nervous System The earthworm’s sensory input and muscular responses are governed by ganglia, which are organized in a segmented manner within the organism. These ganglia, situated along the paired nerve cord, collectively constitute the nervous system of earthworms.

3.3.7 Sensory System Even though earthworms do not possess eyes, they are equipped with specialized receptor cells that enable them to perceive changes in their environment. These specialized sensory organs and chemoreceptors play a crucial role in their ability to respond effectively to various stimuli. The sensory system of earthworms is primarily located in the front part of their body.

3.3.8 Reproductive System Earthworms are hermaphroditic, which means each individual possesses both male and female reproductive systems within their body. The male reproductive system comprises two pairs of testes located in segments 10–11, vasa deferentia extending to the 18th segment, and two pairs of accessory glands situated in the 17th and 19th segments. The prostate and spermatic ducts open through a pair of male genital pores located in the 18th segment. Spermatozoa are stored in the four pairs of spermathecae positioned in segments 6–9. Conversely, the female reproductive system consists of one pair of ovaries and an oviduct. The ovaries connect to an ovarian funnel located beneath them, and they join the oviduct, ultimately opening at the female genital pore in the 14th segment. The two earthworms engage in the reciprocal exchange of their sperm during the process of copulation. Subsequently, the gathered sperm, along with the eggs and nutritive fluids, is placed within a cocoon. This cocoon is subsequently deposited into the soil (Fig. 3.14).

3.3.9 Multiplication of Worms Despite their small size, earthworms offer significant advantages to soil as they enhance aeration through their burrowing activities and enrich it by consuming and excreting organic matter. One common misconception regarding earthworm

3.3  The Morphology and Anatomy of the Earthworm Are Discussed Below

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Fig. 3.14  Reproductive system of earthworms

reproduction is the belief that cutting them in half will result in the regeneration of two new worms. While worms are indeed capable of regenerating certain body segments, they do not reproduce in this manner. The actual reproductive processes of earthworms, involving hermaphroditism and the formation of mucous cocoons, are far more intriguing than these myths suggest.

3.3.10 Earthworm Sexuality Earthworms belong to the annelid phylum. The term “annelid” derives from “small rings,” which aptly describes the appearance of an earthworm’s body when closely examined. These rings are actually segments that provide the worm with flexibility and mobility. While this is visible to the naked eye, what may not be apparent even

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upon close inspection is that earthworms are hermaphrodites, possessing both male and female reproductive organs. Nevertheless, most earthworm species typically require a partner for reproduction despite this anatomical characteristic.

3.3.11 Ready for Reproduction Close to the anterior end of an earthworm lies a smooth ring known as the clitellum. Typically, this band shares the same color as the rest of the worm’s body. However, when earthworms are prepared for mating, the clitellum undergoes a darkening in shade. Although some earthworm species engage in surface mating, which leaves them vulnerable to predators during this critical period, the majority of earthworms prefer underground mating. It is believed that earthworms locate potential mates by emitting pheromones. Once a partner is found, the two worms align themselves in opposite directions, positioning each worm’s male opening with the other worm’s sperm receptacle, referred to as the spermatheca. In this manner, the worms are prepared to exchange sperm.

3.3.12 Copulation and Fertilization After aligning themselves, the male openings of the worms transfer sperm into the spermathecae of their partner. Simultaneously, the clitellum of each worm secretes mucus, forming a tubular structure that fills with a protein-rich fluid known as albumin. Once the sperm exchange is complete, the worms disengage and move away. As they progress, the tubular structure gradually slides off the body of each worm. Along its path, the tube traverses the female reproductive pore, collecting the eggs in the process. Continuing on, the tube passes the spermatheca, gathering the sperm previously deposited during copulation. Once the worm has detached from the tube, the tube seals off, allowing the sperm to fertilize the eggs within. Subsequently, the eggs develop within this protective cocoon.

3.3.13 No Partner Needed While dividing a worm in half does not result in the creation of two new worms, certain earthworm species possess the ability to reproduce independently, a phenomenon known as parthenogenesis. This type of reproduction proves advantageous in habitats where finding a partner is challenging or environmental conditions are consistently changing. Parthenogenic earthworms are typically located in shallow soil or decaying organic matter, while their counterparts that engage in mating with a partner are generally found in deeper soil regions where environmental conditions are more stable. Research conducted by the Department of Biology at the University of Rochester, published in a 1979 issue of the Oxford Journal’s Integrative

3.3  The Morphology and Anatomy of the Earthworm Are Discussed Below

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and Comparative Biology, revealed this distinction. Contrary to prior beliefs, biologists have identified more than 30 species of earthworms within the Lumbricidae family that exhibit this independent mode of reproduction.

“While ending, a picture with a worthy message” “I doubt whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.” ―Charles Darwin on the importance of earthworms

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3  Earthworms, Their Species, and Biological Features

References Adhikary S (2012) Vermicompost, the story of organic gold: a review. Agric Sci 3(7):905–917 Arancon NQ, Edwards CA, Lee S (2002) Management of plant parasitic nematode population by use of vermicomposts. In: Proceedings of Brighton Crop Protection Conference-Pests and Diseases, Brighton, pp 705–716 Arancon NQ, Edwards CA, Yardim EN, Oliver TJ, Byrne RJ, Keeney G (2007) Suppression of two-spotted spider mite (Tetranychus urticae), mealy bug (Pseudococcus sp) and aphid (Myzus persicae) populations and damage by vermicomposts. Crop Prot 26:29–39 Arancon NQ, Edwards CA, Babenko A, Cannon J, Galvis P, Metzger JD (2008) Influences of vermicomposts, produced by earthworms and microorganisms from cattle manure, food waste and paper waste, on the germination, growth and flowering of petunias in the greenhouse. App Soil Ecol 39:91–99 Azarmi R, Giglou MT, Taleshmikail RD (2008) Influence of vermicompost on soil chemical and physical properties in tomato (Lycopersicum esculentum) field. Afr J Biotechnol 7(14):2397–2401 Canellas LP, Olivares FL, Okorokova AL, Facanha AR (2002) Humic acids isolated from earthworm compost enhance root elongation, lateral root emergence, and plasma H+-ATPase activity in maize roots. Plant Physiol 130:1951–1957 Phillips HRP, Guerra CA, Bartz MLC, Briones MJI, Brown G, Crowther TW, Ferlian O, Gongalsky KB, van den Hoogen J, Krebs J, Orgiazzi A, Routh D, Schwarz B, Bach EM, Bennett J, Brose U, Decaëns T, König-Ries B, Loreau M, Mathieu J, Mulder C, van der Putten WH, Ramirez KS, Rillig MC, Russell D, Rutgers M, Thakur MP, de Vries FT, Wall DH, Wardle DA, Arai M, Ayuke FO, Baker GH, Beauséjour R, Bedano JC, Birkhofer K, Blanchart E, Blossey B, Bolger T, Bradley RL, Callaham MA, Capowiez Y, Caulfield ME, Choi A, Crotty FV, Dávalos A, DJD C, Dominguez A, Duhour AE, van Eekeren N, Emmerling C, Falco LB, Fernández R, Fonte SJ, Fragoso C, Franco ALC, Fugère M, Fusilero AT, Gholami S, Gundale MJ, López MG, Hackenberger DK, Hernández LM, Hishi T, Holdsworth AR, Holmstrup M, Hopfensperger KN, Lwanga EH, Huhta V, Hurisso TT, Iannone BV 3rd, Iordache M, Joschko M, Kaneko N, Kanianska R, Keith AM, Kelly CA, Kernecker ML, Klaminder J, Koné AW, Kooch Y, Kukkonen ST, Lalthanzara H, Lammel DR, Lebedev IM, Li Y, Lidon JBJ, Lincoln NK, Loss SR, Marichal R, Matula R, Moos JH, Moreno G, Morón-Ríos A, Muys B, Neirynck J, Norgrove L, Novo M, Nuutinen V, Nuzzo V, Rahman PM, Pansu J, Paudel S, Pérès G, Pérez-Camacho L, Piñeiro R, Ponge JF, Rashid MI, Rebollo S, Rodeiro-Iglesias J, Rodríguez MÁ, Roth AM, Rousseau GX, Rozen A, Sayad E, van Schaik L, Scharenbroch BC, Schirrmann M, Schmidt O, Schröder B, Seeber J, Shashkov MP, Singh J, Smith SM, Steinwandter M, Talavera JA, Trigo D, Tsukamoto J, de Valença AW, Vanek SJ, Virto I, Wackett AA, Warren MW, Wehr NH, Whalen JK, Wironen MB, Wolters V, Zenkova IV, Zhang W, Cameron EK, Eisenhauer N (2019) Global distribution of earthworm diversity. Science 366(6464):480–485. https://doi.org/10.1126/science.aax4851. Erratum in: Science. 2020 Jul 31;369(6503)

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Vermitechnology: History and Its Applications

Vermitechnology plays a significant role within the field of biotechnology, harnessing the capabilities of earthworms to transform diverse organic waste materials into valuable resources. This cutting-edge biotechnological approach offers multiple benefits, including the production of bio-fertilizers in the form of vermicompost for agricultural purposes, as well as the rapid generation of high-quality protein (earthworm biomass) to address the nutritional requirements of animals. Vermitechnology is on the rise as it leverages earthworms to address a range of environmental challenges, encompassing waste management, soil enhancement, and the promotion of sustainable agriculture. Vermitechnology is a self-sustaining, self-regulating, self-improving, and self-­ enhancing technology with minimal to no energy requirements, effectively minimizing waste. It boasts simplicity in construction, operation, and maintenance. What sets it apart from other bio-conversion, bio-degradation, and bio-production technologies is its unique ability to utilize organic materials that would otherwise remain unusable. In comparison to other bio-treatment methods, vermitechnology excels by achieving higher utilization rates than the rates of destruction seen in alternative technologies. Additionally, it offers a substantial value addition, approximately 100–1000 times greater than traditional biological methods. This approach involves the aerobic stabilization of non-hemophilic organisms and a bio-oxidation process for breaking down organic waste. Earthworms play a crucial role in this process, as they aid in fragmenting, mixing, and promoting microbial activity within the waste materials. The fundamental principle underlying vermitechnology is that, during feeding, earthworms break down waste materials, increasing their surface area and thus facilitating the colonization of micro-organisms.

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_4

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4.1 History Charles Darwin is credited as the trailblazer in the realm of vermitechnology studies. He stands as the first individual to illuminate the significance of earthworms within ecosystems. His seminal work, titled “The Formation of Humus Through the Action of Earthworms,” was published in 1881. Since that pivotal moment, vermitechnology has been embraced by nations across the development spectrum for various organic waste management applications. Notably, this approach has found commercial adoption in the USA and Canada, and it has proven to be an efficient solution in the Philippines and other parts of Asia. • Vermitechnology has been developed through the years since the first vermiculture experiments were conducted in Holland 1970 and subsequently in Canada and England. • The first vermicompost farm was established  in the year 1978–1979 by the American Earthworm Technology Company. • A biology educator hailing from Michigan, Mary Appelhof is widely recognized as the pioneer of small-scale vermicomposting. She introduced the concept of home vermicomposting back in 1972. • In the following year, 1973, she elucidated her method in a concise two-page pamphlet titled “Basement Worm Bins Produce Potting Soil and Reduce Garbage.” • By 1979, she had expanded her knowledge into a comprehensive four-page brochure entitled “Composting Your Garbage with Worms. • The culmination of her work came in 1982 when her book “Worms Eat My Garbage” was published, solidifying her legacy in the field. Vermitechnology comprises three main processes: It is engaged to achieve one, or more, of the following three outcomes: 1. Vermiconversion technology: Mass maintenance of sustainability of waste lands through earthworms. Waste management technology through vermi-­ conversion. It is used to reduce organic waste volumes through vermistabilization. 2. Vermicomposting technology: The utilization of earthworms in a biodegradation process to convert waste biomass into vermicast, serving both agricultural and environmental management objectives. 3. Vermiculture technology: Rearing of earthworms to produce earthworm biomass.

4.2 Wastes Utilized in Vermitechnology Earthworms readily consume various forms of non-toxic organic waste materials commonly generated in natural settings. These abundant organic waste sources are typically produced in forests, agricultural areas, and urban environments. They

4.3  Earthworms Used in Vermitechnology

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encompass a range of materials, including kitchen waste, produce market discards, sewage sludge, yard debris, animal waste, weed matter, coir residues, leaf litter, paper and pulp by-products, surplus animal feed, aquatic biomass, and more. Inadequate disposal of these organic waste materials in an unscientific manner can give rise to a range of problems, including the proliferation of flies, disturbances caused by pigs, the spread of pathogens, soil and air pollution, contamination of surface and groundwater, and the release of unpleasant odors. The bio-degradable and decomposable organic waste materials that are suitable for use as composting materials in vermitechnology include: Animal dung: Cattle, poultry, goat, sheep, and horse wastes, etc. Agricultural wastes: Agri-wastes obtained during and after harvesting and threshing. Forestry wastes: Wood shavings, peels, sawdust, and pulp, etc. City garbage and leaf litter: Kitchen wastes and leaf litter of street plants and residential areas. Paper and cotton industry wastes: Wastes generated from cotton cloth and paper industry.

4.3 Earthworms Used in Vermitechnology Vermitechnology is predominantly reliant on a limited selection of epigeic and anecic earthworm species on a global scale for producing vermicompost and worm biomass. In India, specifically, there is a notable focus on three species that find extensive application in vermiculture and vermicomposting practices, including: 1. Eudrilus eugeniae 2. Eisenia foetida 3. Perionyx excavates

African night crawler European night crawler Oriental worm

Numerous other species may have the potential for utilization, yet their suitability must be evaluated through various considerations such as adaptability to local climate conditions, feeding and reproduction rates, lifespan, geographic distribution, and availability, among other factors.

4.3.1 Earthworm Species Suitable for Waste Degradation Extensive research in vermiculture has demonstrated that the red tiger worm (Eisenia andrei), tiger worm (Eisenia foetida), the Indian blue worm (Perionyx excavatus), the African night crawler (Eudrilus eugeniae), and the red worm (Lumbricus rubellus) stand out as the most suitable species for vermicomposting.

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4.4 Role of Earthworms in Vermitechnology Earthworms serve as integral detritus consumers, actively participating in the organic matter decomposition and soil metabolism processes. Their importance has led to the evolution of vermitechnology, which incorporates both surface dwelling and subsoil native earthworm varieties for composting and soil enhancement. Consequently, vermicomposting efficiently recycles organic waste, yielding valuable products such as vermicompost and vermiwash, which have demonstrated their significance in promoting plant growth and overall productivity (Fig. 4.1).

4.4.1 Effects of Earthworms on (a) Soil physical properties: Through the ingestion of soil, breakdown, and the casting process, earthworms contribute to the formation of soil aggregates, enhancing soil aeration and porosity. (b) Soil chemical properties: Earthworms facilitate the mineralization of organic matter, releasing nutrients in forms accessible to plants. (c) Micro-organism status in soil: Numerous micro-organisms in the soil remain dormant with limited metabolic activity, awaiting favorable conditions such as those found in the earthworm gut or mucus to become active. Earthworms have been demonstrated to boost overall microbial respiration in the soil, thereby promoting the microbial degradation of organic matter. (d) Plant growth: Earthworms release substances such as auxins and cytokinins along with the macro and micronutrients present in vermicasts which are beneficial to plant growth. (e) Land reclamation: Stimulating the growth of earthworms helps in improving impoverished soils. (f) Organic solid waste management: Earthworms have the capacity to efficiently handle various types of waste, including household garbage, sewage sludge, municipal refuse, and waste from the wood, paper, and food industries. In tropical and subtropical climates, Eudrilus eugeniae and Perionyx excavatus emerge as the top choices for vermicomposting earthworms when it comes to managing organic solid waste.

4.4  Role of Earthworms in Vermitechnology

Fig. 4.1  Processes involved in the organics degradation by earthworm and cast production

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4  Vermitechnology: History and Its Applications

4.5 Applications of Vermitechnology 1. Water treatment (vermifiltration): It is the processes where wastewater is treated, using waste eater earthworms. The earthworm body serves as the bio-­ filter and revives waste from the wastewater through ingestion and bio-­ degradation and also absorption through their body walls. They feed on harmful and ineffective micro-organisms in the wastewater, selectively avoiding effective bio-degrading micro-organisms. It is advantageous over conventional treatments as this does not produce sludge (worms eat the sludge and converts it to vermicast) and odor (feed on rotting and decaying matter, thus reducing formation of foul odors). 2. Soil detoxification: Earthworms can be used to biodegrade chemical soil contaminants. Compared to conventional methods it is least expensive and is internationally acceptable. Earthworm species such as E. fetida are highly resistant to several chemical contaminants such as heavy metals and organic pollutants in soil which accumulate in their tissues (Fig. 4.2). 3. Production of bio-fertilizers and improving soil fertility: Vermicompost and vermiwash can be used in place of agro-chemicals. These are result of the metabolic action of the earthworms. They excrete effective and useful soil microbes and are involved in secretion of proteins, polysaccharides, and other nitrogen containing compounds into the soil around them. They fragment the soil and increase proper circulation of air and facilitate dispersion and soil turning in farmlands. Earthworm biomass is used in animal feed production and for human dietary supplements. They are rich in proteins, minerals, vitamins, and roughages. Their protein is of high quality and contains all essential amino acids, in higher quantities than in animal feeds. 4. Processing and managing solid organic wastes: With the help of vermicomposting the solid organic wastes can be processed and turns them into useful resources, which can be used in agriculture. 5. Vermiremediation technology: This innovative approach is aimed at cleansing chemically contaminated sites, improving their physical, chemical, and biological properties to make them suitable for reuse. 6. Vermi-agro-production technology: It focuses on rejuvenating and enhancing soil fertility to yield safe, chemical-free food, utilizing vermicompost, thus eliminating the need for harmful agro-chemicals. 7. Vermiprotection technology: It explores the potential of harnessing earthworms to develop modern vermimedicines to combat chronic and life-­threatening diseases, ultimately safeguarding human health. 8. Vermiproduction technology: Leveraging earthworms to manufacture valuable raw materials for applications in the rubber, soap, lubricant, detergent, and cosmetics industries, as well as using rich worm proteins as feed materials (vermimeals) to support fishery, dairy, and poultry sectors in producing more nutritious food for the community.

4.6  Issues Related to Vermitechnology

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Fig. 4.2  Heavy metal accumulation by chloragogen cell of earthworm

4.6 Issues Related to Vermitechnology The main issue surrounding the effective practice of vermitechnology is the lack of information. Seeing as this is an efficient, low-cost method of waste management, it is disheartening to note that millions of people do not know about this and the problem of organic waste management remains an issue. This problem can be solved by raising awareness on the benefits of earthworm technology. (a) Time-consuming: It takes about 6 months for earthworms to degrade organic matter and transform it to useful content, as in other composting methods organic matter processing can be done in 3 months. (b) Bad odor: This would be a problem particularly for small scale or home vermicomposting owners. If just a few factors are not managed effectively, vermicompost bins can produce effective odors. As an example, poor ventilation for the worms, overfeeding, and even utilizing too much wet feed can result in bad odor. To avoid this problem, vermicompost owners have to ensure that the factors are well managed and maintained. (c) High maintenance: The worms have to be properly taken care off. As they can consume large quantities of organic matter, they have to be fed constantly, but then the feeding has to be monitored to prevent the worms from being overwhelmed with too much to eat. Moisture levels and pH levels also have to be monitored. (d) Pest and pathogen problems: While the heat generated from other compost methods helps to kill pathogens and pests. Vermitechnology is at disadvantage as earthworms cannot survive high temperatures. The vermicompost bins must be kept at temperature cool enough for the earthworms to survive. Because of this vermicompost can be home to some pathogens and pests found in parent soil material.

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(e) Harvesting time: Harvesting the final products of vermicomposting out of a vermicompost system should be done carefully. This is done by sorting and taking out the worms as the soil amendment is collected. This takes time, depending on how big the vermicompost bin is and size of worm biomass used.

4.7 Vermitechnology in Other Countries The utilization of vermitechnology in agriculture is not a recent innovation. Nevertheless, the production of organic manure through vermitechnology represents a relatively new concept. Currently, both vermiculture and vermicomposting have become established practices across developed and developing nations worldwide. The concept of vermitechnology emerged in the mid-twentieth century, with the establishment of the first vermicompost plant in Holland in 1970, subsequently followed by England and Canada. Vermiculture practices then spread to countries such as the USA, Italy, Philippines, Thailand, Chita, Korea, Japan, Brazil, France, Australia, and Israel. Vermicomposting facilities are known to be in commercial operation in Japan, Canada, the USA and have also been effectively implemented in the Philippines and throughout Asia (Sharma et al. 2005). (a) Japan: Japan has a significant worm production industry, with an output of approximately 3000 million tons, largely for managing extensive paper and spinning mill waste (Senapati and Julka 1993). For instance, the Toyhira Seiden Kogyo Co. in Japan utilizes materials like rice straw, municipal sludge, sawdust, and paper waste for vermicomposting across 20 plants, collectively producing 2–3 thousand tons per month (Edwards and Arancon 2004). The Aoka Sangyo Co. Ltd. in Japan operates three waste processing facilities, capable of handling 1000 tons of waste from pulp and food industries (Kale 1998). In a different study, Sharma et al. (2005) noted the presence of around 3000 additional vermicomposting plants in Japan, each with a waste processing capacity ranging from 5 to 50 tons per month. (b) Canada: As per Ghosh (2004), commercial-scale vermicomposting commenced in Ontario, Canada, as recently as 1970, and is currently managing approximately 75 tons of waste per week. Edward’s report from 2000 indicates that the American Earthworm Company (AEC) was founded in 1978–1979, with a processing capacity of about 500 tons per month. (c) USA: Collier (1978) highlighted the utilization of vermiculture in the USA for managing swedge sludge and effluents from densely populated livestock facilities. In Wilson, North Carolina, over 5 tons of pig manure (excreta) undergo vermicomposting on a weekly basis, as reported by NCSU in 1997. In Florida, Eastman et al. (2001) conducted experiments to assess the viability of vermicomposting as a method for eliminating human pathogens, with the aim of achieving United States Environmental Protection Agency (USEPA) Class A stabilization for domestic bio-solids. The results indicated that vermiculture can effectively serve as a USEPA-compliant process for pathogen treatment and the potential production of class A biosolids.

4.7  Vermitechnology in Other Countries

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(d) Australia: In Australia, vermiculture is gaining widespread adoption, ranging from home-based worm bins to large-scale composting initiatives that target municipal bio-solids and yard trimmings. As a result, thriving industry is emerging to support these advancements. At the household level, vermicomposting of food scraps has become increasingly popular, leading to the development and marketing of home worm bins by several entrepreneurs. An illustrative example of vermiculture’s successful implementation can be found in the 1996 Summer Olympics held in Sydney, Australia. During the event, Australians utilized earthworms to manage and process a substantial volume of waste generated. They soon discovered that the waste produced by these worms yield significant benefits for their plants and soil. In Redlands, Queensland, the vermitech operation has devised a cost-effective system capable of consistently stabilizing a wide range of organic waste materials on a large commercial scale. Moreover, extensive research on vermiculture and its environmental management implications is actively underway at various academic institutions across Australia, including Murdoch University in WA, the University of Western Sydney in NSW, Southern Cross University in NSW, the University of Queensland in Brisbane, and Griffith University in Brisbane, QLD. (e) New Zealand: In New Zealand, Springett and Syers (1979) conducted a study where they cultivated ryegrass both with and without earthworm casts from the field worm Lumbricus rubellus. Their findings consistently showed enhanced plant growth in the presence of earthworm casts. (f) Germany: Researchers in Germany, Graff and Makeschin (1980) reported that soils processed by worms exhibited a notable increase in dry matter and root production for ryegrass. (g) UK: Recent studies conducted by the Open University and the Worm Research Centre, focusing on the extensive vermicomposting industry, indicate the presence of several hundred large-scale vermicomposting facilities in the UK. Moreover, there are minimum of six companies involved in the marketing and establishment of large-scale outdoor worm composting systems within the country. (h) Other countries: The most extensive vermiculture endeavor is undertaken by the Hobart City Council in Tasmania. They employ worms to process approximately 66 cubic yards of municipal bio-solids on a weekly basis, as documented in Appelhof et al. (1996). Additionally, in Colombia, where over 1 million tons of coffee pulps are generated annually, the traditional practice of transformation through turned piles has resulted in a final product with suboptimal physical and chemical properties. In response, vermicomposting has been proposed as an alternative method to convert these wastes into a valuable organic fertilizer, as suggested by Orozco et al. (1996). At the University of Idaho in Moscow, Idaho, researchers have conducted a series of experiments aimed at assessing the efficacy of composting and vermicomposting as advantageous management practices for fish manure in aquaculture (Riggle 1998). In Italy, vermiculture is employed to biodegrade both paper mill and municipal sludge. This process involves the mixing and aeration of aerobic and

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4  Vermitechnology: History and Its Applications

anaerobic sludge for over 15  days, with the addition of 5  kg of earthworms to 5000 cubic meters of sludge. After approximately 8 months, the sludge undergoes transformation into vermicompost (Ceccanti and Masciandaro 1999). Meanwhile, in France, a daily vermicomposting operation processes 20 tons of mixed household wastes, utilizing 1000–2000 million red worms (Eisenia andrei) within earthworm tanks (ARRPET 2005). In Hong Kong, a study by Chan and Griffiths (1988) involved preparing vermicomposting from pre-treated pig manure using Eisenia foetida to create humus-rich worm castings, which were found to have a stimulating effect on Glycine max (Soybean). In an underdeveloped country like Nepal, an NGO called Pesticide Monitor Nepal, with support from the United Nations Development Programme and the Global Environment Facility, initiated a vermicomposting project aimed at managing unprocessed waste, such as elephant dung, engaging 12 rural women. Between May and June 2008, these women collectively earned ₹24,000  (INR) by selling 2 tons of vermicompost. Witnessing the success of this endeavor, an additional 60 women initiated their own vermicomposting activities at home.

4.8 Vermitechnology in India Vermitechnology holds significant potential in India due to the continuous generation of both rural and urban biomass waste, along with the ample workforce available to manage it. However, in India, vermiculture is still in its developmental stages. For over a decade now, farmers, agro-based industries, and urban households have been engaging in the cultivation of earthworms as a biological resource for managing organic waste. Despite these efforts, India has yet to fully harness the potential of vermiculture for waste disposal and the production of fertilizers. Considering the substantial amount of waste generated in the country, India has the capacity to produce around 400 million metric tonnes of plant nutrients through vermiculture, thus significantly reducing the need for foreign exchange expenditure on fertilizer imports. In India, vermiculture is primarily employed for the purpose of recycling organic waste materials. Increased awareness within the farming community regarding the nutrient imbalances in soil has prompted the adoption of technologies aimed at accelerating the decomposition of organic residues and their subsequent return to the soil (Kale 1994). Notably, two innovative vermicomposting initiatives have been implemented to manage urban waste in Hyderabad. One initiative involves a network of small-scale vermicomposting sites dispersed throughout the city, while the other encompasses a larger facility situated on the city’s outskirts. Gupta and Garg (2008) documented that since 1985, an organization in Maharashtra has encouraged over 2000 farmers and institutions to transition from conventional chemical practices to vermicomposting. In 1985, Maharashtra Agriculture Biotech established a small plant dedicated to the production of vermicompost from agricultural waste materials, and presently, it yields an annual output of 5000 metric tons of vermicompost.

4.8  Vermitechnology in India

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The Bhawalker Earthworm Research Institute (BERI) in Pune stands out as a pioneering organization deeply engaged in vermiculture, specifically in the vermicomposting of solid wastes and the application of vermifiltration for sewage treatment in India, a commitment dating back to the 1970s. Today, nearly all agricultural universities in the country have actively embraced vermiculture. A transformative movement is gaining momentum across the subcontinent, with a special focus on involving economically disadvantaged rural women who have a dual objective: “making wealth from waste” while simultaneously contributing to environmental cleanliness. Earthworms have significantly improved the quality of life for many impoverished individuals. In numerous Indian villages, non-governmental organizations (NGOs) are providing cement tanks free of charge and encouraging women to gather waste materials from their communities, engage in vermicomposting, and subsequently sell the resulting vermicompost to local farmers. In Tamil Nadu, specifically at Periyar College of Technology, there is a well-­ established commercial-scale vermicomposting operation conducted in windrows. Exotic earthworms of the Eisenia fetida species are employed in this process, resulting in the recovery of approximately 30–40% of the waste as valuable vermicompost. This high-quality compost is made available to local farmers, and a portion of the revenue generated is reinvested in maintaining the wormery (ARRPET 2005). Additionally, the government agencies in Karnataka are involved in the realm of vermicomposting. The existence of the Karnataka Compost Development Corporation (KCDC) underscores the significant role vermiculture plays within the state. KCDC specializes in producing compost from urban waste and supplies it to the city for use in kitchen gardens. Furthermore, a study conducted by Gandhi et al. (1997) compared traditional Indian composting methods with vermicomposting, particularly using kitchen waste as the substrate. Their findings indicate that vermicomposting is a more suitable and effective approach compared to traditional composting techniques. In a separate study, Kaushik and Garg (2004) highlighted the challenge of managing the substantial annual production of textile mill sludge in India, underscoring that vermicomposting, when appropriately mixed with cow dung, serves as a viable technology for waste management. Agricultural experts at the University of Agricultural Science, Bangalore, have developed comprehensive expertise in vermicomposting suitable for Indian conditions, utilizing Eudrilus eugeniae. Furthermore, they have introduced a vermicompost product (Vee coup E.83UAS) for field trials in the region of South India, characterized by a tropical climate (Julka 1993). A multiplication experiment was carried out at the International Crop Research Institute for Semi-Arid Tropics (ICRISAT) involving three earthworm species, namely Eisenia foetida, Perionyx excavatus, and Eudrilus eugeniae. They were provided with feed materials comprising wheat straw, tree leaves, chickpea straw, and parthenium mixed with cow dung. ICRISAT, with support from the Asian Development Bank (ADB), Philippines, the District Waste Management Agency (DWMA) of the Government of Andhra Pradesh, and the TaTa-ICRISAT-ICHR projects in northeastern regions of India, was enthusiastic about promoting vermiculture technology, as reported in SAT eJournal. In another study, Manna et  al.

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(2003) examined the influence of three earthworm species, Eisenia foetida, Perionyx excavatus, and Dichogaster bolaui, on the decomposition of forest litters from Tectona grandis (Teak), Madhuca indica (Mahua), and Butea monosperma (Palas). Their research focused on maintaining quality in a vermicomposting system and assessing the impact of applying in situ prepared vermicompost on the growth of forest trees. The study found that Tectona grandis was the most suitable raw material for earthworm activity. Julka (1993) pointed out that the Indian subcontinent boasts a highly diverse and abundant earthworm population, consisting of approximately 509 species distributed across 10 families and 67 genera. Furthermore, Bhole (1992) reported roughly 3000 earthworm species in India, highlighting their various applications in vermicultural practices over time. However, not all of these earthworm species are well-­ suited for vermicomposting. Typically, epigeic earthworms that primarily consume carbon-rich substrates are the most adapted for vermicomposting (Blakemore 2000). Sathianarayanan and Khan (2006) conducted a study of earthworm diversity in the Pondicherry region and found that the highest diversity of earthworms was observed in vermiculture areas, while the lowest diversity was found in saline habitats. Similarly, Singh (1997) conducted an extensive survey in the Varanasi region, concluding that Dichogaster bolaui, Lampito mauritii, and Eutyphoeus incommodus were among the potential earthworm species suitable for enhancing soil fertility and decomposing organic waste. At the Central Plantation Crops Research Institute (CPCRI) in Kahikuchi, a vermicomposting initiative was launched involving the utilization of dry coconut and arecanut leaves. Eudrilus sp., a local strain of earthworm similar to Eudrilus eugeniae, was employed for this purpose, a strain developed at CPCRI, Kasaragod. The resulting vermicompost was then applied to coconut and arecanut crops during the pre-monsoon period, as detailed in Minimission-I Bulletin from CPCRI, Kahikuchi. The vermicompost derived from coconut leaves exhibited an average nutrient content of 1.2% N, 0.1% P2O5, and 0.5% K2O.  In contrast, vermicompost produced from household waste displayed an average nutrient composition of 1.8% N, 1.9% P2O5, and 1.6% K2O.

4.9 Vermitechnology in Northeast India In contrast to nationwide and regional movements promoting vermiculture, the adoption of vermitechnology in the Northeastern region, particularly in Assam, has not gained significant momentum. In this part of Northeast India, traditional silk-­ producing farms, known as “muga farms,” predominantly utilize exotic earthworm species like Eudrilus eugeniae for the preparation of vermicompost, which is then used as a natural fertilizer for muga host plants. In Assam, non-governmental organizations (NGOs) and various Self Help Groups are actively engaged in the production and sale of vermicompost, making use of efficient exotic earthworm species. A vermicompost product known as “black gold” is marketed by North East Green Tech Private Ltd., in Guwahati. This company has imported earthworm technology

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from Bangalore, and they gather the required organic waste materials from vegetable markets in Guwahati. Furthermore, Goswami (2002) conducted a study that focused on assessing earthworm species in Assam for their suitability in the bio-management of municipal solid waste (MSW). Her research unveiled the presence of 16 earthworm species in Assam, with Amynthas diffringens displaying the highest effectiveness in decomposing MSW. In a separate study, Sannigrahi (2005) engaged in preparing vermicompost with paddy straw, treating it with chemical fertilizers including Perionyx excavatus. The findings indicated that the addition of urea delayed the vermicomposting process, although it was unaffected by the inclusion of rock phosphate and murate of potash. In another study, Sannigrahi (2005) compared the efficiency of Perionyx excavatus and Eisenia foetida in vermicomposting thatch grass (Imperata cylindrical).” In the natural settings of Manipur, the practices of vermiculture and vermicomposting have been steadily gaining traction over the past few years. In this region, four earthworm species, namely Eudrilus eugeniae, Eisenia foetida, Perionyx excavatus, and Pheretima elongata, are commonly cultured for vermicomposting purposes. Chaudhuri and Bhattacharjee (2005) conducted research on earthworm bio-diversity in Tripura to support the efficient utilization of earthworm resources in vermitechnology. Their findings documented 21 earthworm species across 10 genera and 5 families. Additionally, Bhadauria and Ramakrishnan (1991) undertook a comparative analysis of earthworm populations in the Serai Khasi pine forests of Meghalaya. They identified species such as Towossolar horaii, Amynthus diffringens, Eulyphorus festinus, Perionyx sp., and Drawida assamensis in all types of forest ecosystems, highlighting their potential for vermiculture due to their wide-­ ranging adaptability.

4.10 Recent Works Related to Vermitechnology 4.10.1 Aerobic Sponge Method Vermitechnology for Macro-Level Conversion of Organic Garbage Seenappa (2012) introduced the aerobic sponge method vermitechnology (ASMV) designed for large-scale transformation of organic waste. The ASMV technology is executed in two distinct phases: Phase-I: This involves the separation of recyclable and non-biodegradable waste from the unsegregated waste at the designated site or source. Simultaneously, the segregated waste is prepared for appropriate placement. Phase-II: ASMV technology is then applied for the complete conversion of organic waste into vermicompost, utilizing the traditional composting earthworm, Eudrilus eugeniae. Given that Indian wet waste constitutes an average of 60% of the total waste generated in urban areas, this method readily enables the conversion of such waste into organic products.

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4.10.2 Treatment of Agricultural Wastes with Biogas: Vermitechnology Kovshov and Skamyin (2017) employed agricultural waste, including cattle manure, chicken manure, swine manure, and various combinations thereof, for concurrent treatment using both biogas and vermitechnology. To facilitate this process, they constructed a specialized biogas-vermitechnological setup. In the biogas phase, a unique organic catalyst containing glucose and cellulose was introduced. This served as a source of biogas bacteria and helped modify the C/N ratio of the fermented substrate to achieve a C/N ratio of 30/1. For the vermitechnological stage, earthworms, specifically Eisenia foetida, were utilized. The study involved the processing of cattle manure alone and in combination with leaves (at a ratio of 4:1 by weight) to produce vermicompost. The resulting bio-humus from this approach was discovered to be notably consistent and devoid of heavy metal contaminants. An additional benefit of this method is that it can leverage the heat generated by the biogas, enabling the vermicomposting process to continue even during colder seasons.

4.10.3 Assessment of Different Organic Supplements for Degradation of Parthenium Hysterophorus by Vermitechnology Yadav (2015) conducted the preparation of compost using Parthenium hysterophorus, along with farm and animal wastes, which were subsequently decomposed using a tank method involving Eisenia foetida. The resulting vermicompost was observed to exhibit high quality akin to that of any organic fertilizer. The findings demonstrated the economic viability of vermicompost production, given its utilization of locally available resources and its environmentally friendly technology. This approach can be readily adopted by farmers to enhance crop productivity and sustain soil fertility through the utilization of locally accessible organic waste materials.

4.10.4 Application of Vermitechnology in Aquaculture Sustainable aquaculture aims for enduring practices achieved through the utilization of renewable resources. Organic aquaculture represents a production system that minimizes or largely excludes the use of synthetic compounds. In low-cost organic aquaculture systems, the pre-dominant reliance is on vermitechnology, particularly vermicompost and its by-products, which occur naturally. Earthworms play a unique role as a source of fish food, providing essential iron for fish development. Adult earthworms, cocoons, and vermiwash can effectively serve as fish feed in various ways. Hence, the integration of vermitechnology is essential for the advancement of organic aquaculture.

References

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4.10.5 Vermitechnology for Organic Waste Management and Sustainable Agriculture (Gopi 2017; Chattopadhyay 2017) Sustainable agriculture is an essential requirement for the future, ensuring economic security, ecological stability, and food security for the growing global population. Vermitechnology, whether it involves low or high-tech approaches, can play a contributory role in organic waste management and the promotion of sustainable agriculture. It achieves this by transforming diverse waste materials into valuable products, which serve as nutrient-rich alternatives to synthetic chemicals.

4.11 Future Prospects Vermitechnology can be used to drive the world into an era of efficient production of agricultural products and solid waste management. Sugar industries burn their waste; this leads to increase in the carbon contents of the atmosphere and promotes global warming. Apart from the effects on the atmosphere, burning also affects soil texture and nutrients. Managing these wastes through vermicomposting will be a bold step to securing a safe future. Also products of vermitechnology, like vermicompost, vermiwash, and vermicast can be used as bio-fertilizers so as to reduce the use of agro-chemicals, thereby increasing food production, improving soil health and reducing pollution that arises as a result of runoff of agrochemicals from soil surface. Incorporating earthworm proteins into animal feeds can also help to reduce cost on fish meal production while yet providing a better source of protein and nutrients leading to food production and economic stability. The world’s population is estimated to grow at an average rate of 83  million people per year. Thus, the need of efficient organic waste management systems help to reduce the strains on the already set systems. Therefore, vermitechnology can be used to improve the country’s approach to organic waste management and agricultural industry productivity. It can be used to reduce the application of agro-chemicals and for bio-fertilizer production and even for bio-control of some pathogens. Vermitechnology can be employed for bio-­ degradation and land remediation. By culturing and employing the use of earthworms moderately polluted soils can be vermiremediated.

References Appelhof M, Webster K, Buckerfield J (1996) Vermicomposting in Australia and New Zealand. Biocycle 3:63–66 ARRPET (2005) Vermicomposting as an eco-tool in sustainable solid waste management. The Asian Regional Research Program on Environmental Technology, Asian Institute of Technology, Anna University, India

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Bhadauria T, Ramakrishnan PS (1991) Population dynamics of earthworms and their activities in forest ecosystems of north-east India. J Trop Ecol 7:305–318 Bhole RJ (1992) Vermiculture biotechnology basis, scope for application and development. In: Proceedings of the National Seminar Organic Farming held at College of Agriculture, Pune, 28–29 Jan 1992 Blakemore RJ (2000) Vermiecology I – ecological consideration of the earthworm species used in vermiculture. In: Vermillennium—International conference on vermiculture and vermicomposting, Kalamazoo Ceccanti B, Masciandaro G (1999) Vermicomposting of municipal paper mill sludge. Biocycle 6:71–72 Chan PLS, Griffiths DA (1988) The vermicomposting of pre-treated pig manure. Biol Wastes 24:57–56 Chattopadhyay K (2017) Organic waste management by vermitechnology. Int J Eng Sc Invent 6:2319–6726 Chaudhuri PS, Bhattacharjee G (2005) Earthworms of Tripura, (India) Ecology, Environment and Conservation, 11(2):295–301 Collier J (1978) Use of earthworms in sludge lagoons. In: Hartenstein R (ed) Utilization of soil organisms in sludge management, Virginia, pp 133–137 Eastman BR, Kane PN, Edwards CA, Trytek L, Gunadi B, Sterman AL, Mobley JR (2001) The effectiveness of Vermiculture in human pathogen reduction for USEPA biosolids stabilization. Compost Sci Util 9(1):38–49 Edwards CA, Arancon N (2004) Vermicompost suppresses plant pests and disease attacks. Rednova News Gandhi M, Sangwan V, Kapoor KK, Dilbaghi N (1997) Composting of household wastes with and without earthworms. Environ Ecol 15:432–434 Ghosh C (2004) Integrated vermi-pisciculture––an alternative option for recycling of solid municipal waste in rural India. Bioresour Technol 93(1):71–75 Gopi P (2017) Vermitechnology, a scenario of sustainable agriculture—a mini review. VISTAS 6(1):51–56 Goswami B (2002) Vermitechnological evaluation of earthworm species of Assam for biomanagement of urban organic solid waste. Doctoral thesis, Gauhati University Graff O, Makeschin F (1980) Beeinflussung des Ertrags von Rogenwurmern dreier verschiedener Arten. Pedobiologia 20:176–180 Gupta R, Garg VK (2008) Stabilization of primary sewage sludge during vermicomposting. J Hazard Mater 153:1023–1030. https://doi.org/10.1016/j.jhazmat.2007.09.055 Julka JM (1993) Earthworm resources of India and their utilization in vermiculture. In: Earthworm resources and vermiculture. Zoological Survey of India, Calcutta, pp 125–131 Kale RD (1998) Earthworm: Cinderella of Organic Farming. Prism Books, Bangalore Kale, R.D., Seenappa, S.N. and Jaganatha Rao, C.B. 1994. Sugar factory refuse for the production of vermicompost and worm biomass. 5th International Symposium Earthworms, Ohio University, Columbus, U.S.A. Kaushik P, Garg VK (2004) Dynamics of biological and chemical parameters during vermicomposting of solid textile mill sludge mixed with cow dung and agricultural residues. Bioresour Technol 94:203–209 Kovshov SV, Skamyin AN (2017) Treatment of agricultural wastes with biogas–vermitechnology. Environ Earth Sci 76:660 Manna MC, Jha S, Ghosh PK, Acharya CL (2003) Comparative efficacy of three epigeic earthworms under different deciduous forest litters decomposition. Bioresour Technol 88:197–206 NCSU (1997) Large scale vermicomposting operations —data from Vermicycle Organics, Inc. North Carolina State University, Raleigh Orozco FH, Cegarra J, Trujillo LM et al (1996) Vermicomposting of coffee pulp using the earthworm Eisenia fetida: effects on C and N contents and the availability of nutrients. Biol Fertil Soils 22:162–166

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Riggle D (1998) Vermicomposting research and education. Environmental Service Industry, JG Press, pp 54–56 Sannigrahi AK (2005) Efficiency of Perionyx excavates in vermicomposting of thatch grass (Imperata cylindrica) in comparison to Eisenia foetida in Assam. J Indian Soc Soil Sci 53(2):237–239 Sathianarayanan A, Khan AB (2006) Diversity, distribution and abundance of earthworms in Pondicherry region. Trop Ecol 47(1):139–144 Seenappa SN (2012) Larm as a necessity during composting and/or vermicomposting of kitchen refuses. Univers J Environ Res Technol 2(1):97–100 Senapati BK, Julka LM (1993) Selection of suitable vermicomposting species under Indian conditions. In: Earthworm resources and vermiculture. Zoological Survey of India, Calcutta, pp 113–115 Sharma S, Pradhan K, Satya S, Vasudevan P (2005) Potentiality of earthworms for waste management and in other uses—a review. J Am Sci 1:4–16 Singh J (1997) Habitat preferences of selected Indian earthworm species and their efficiency in reduction of organic material. Soil Biol Biochem 29:585–588 Springett JA, Syers JK (1979) The effect of earthworm casts on ryegrass seedlings. In: Crosby TK, Pottinger RP (eds) Proceedings of the 2nd Australasian conference on grassland invertebrate ecology. Government Printer, Wellington, pp 44–47 Yadav RH (2015) Assessment of different organic supplements for degradation of Parthenium hysterophorus by vermitechnology. J Environ Health Sci Eng 13:44

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Role of Earthworms in Vermicomposting

An earthworm is a segmented worm; a terrestrial invertebrate belonging to the phylum Annelida, Class Chaetopoda, and Order Oligochaeta occupy unique position in animal kingdom. They are the common inhabitants of moist soil and feed on organic matter. Earthworms are considered as the world’s best natural recyclers of biological waste. They play a major role in speeding up breakdown and degradation of organic matter and nutrient cycling and altering the soil structure conclusively molding the structure and composition of the above soil plant population. They effectively utilize various types of organic wastes such as cattle dung, agricultural residue, livestock excreta, and other agro-industrial refuse. Earthworms act as waste managers and aids in changing the physiochemical properties of organic wastes. They make any material more favorable for further decomposition by the microbiota by increasing its surface area. The main activity of earthworms of converting organic matter into soil humus involves the ingestion of soil, fragmentation of organic waste substrates and mixing of different soil components, stimulate microbial activity and increase the rate of mineralization. Studies suggested that in sustainable agriculture organic waste can be managed through the process of vermicomposting by using different species of earthworms which helps in discouraging the use of chemical fertilizers. Earthworms play an important role in enhancing the fertility status of the soil. The burrowing activity of earthworms leads to mixing of soil layers and organic matter present in the soil and hence distribute the organic matter through the soil. Earthworms bring the nutrients from the deeper layers of soil to the soil surface which results in reduced leaching of nutrients and the nutrients are made available to the plants in a usable form. The castings of earthworms are rich in NPK, micro-­ nutrients, and beneficial soil microbes (Bhawalkar and Bhawalkar 1993; Bhat and Khambata 1996). Earthworm feed on the bulk of litter but barely a considerable amount of consumed material (5–10%) is assimilated by the earthworms and the remaining material is ejected out as castings of earthworms (Bhawalkar and Bhawalkar 1993; Bhat and Khambata 1996). Earthworm castings produce plant © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_5

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growth regulator, auxin which is responsible for root growth. Due to auxin, roots grow quickly and intensely. The nitrogen fixation activity is also higher in earthworm casting in comparison to soil because of the existence of nitrogen-fixing bacteria in both earthworm gut and casts (Edwards and Bohlen 1996).

5.1 Earthworm Species Suitable for Vermicomposting Out of the 3200 earthworm species documented worldwide, the Indian subcontinent hosts 509 species from 67 different genera. Within the diverse habitats of India, approximately 374 species have been identified (Senapati and Julka 1993). Among these, several epigeic earthworms, characterized by their innate ability to thrive in organic waste environments, display resilience to a broad spectrum of environmental conditions, possess short life cycles, high reproductive rates, and efficiently consume, digest, and assimilate organic matter. These qualities make them highly suitable for vermicomposting (Dominguez et al. 1997). A selective group of earthworm species exhibit all these desirable characteristics and are particularly well-­ suited for vermicomposting. These species include Eisenia foetida, Eudrilus eugeniae, Eisenia andrei, Dendrobaena veneta, and Perionyx excavatus. Additionally, some other species such as Dichogaster modigliani, Drawida nepalensis, Lampito mauritii, Lumbricus rubellus, and Dendrobaena rubida have also been employed to a certain extent in vermicomposting practices (Bhattacharya and Chattopadhyay 2002; Padmavathiamma et al. 2008). For bio-solid waste management, Epigeics species are most suitable as these worms can accelerate the process of composting to a great degree and results in the generation of improved quality of vermicomposts, in comparison with those prepared through traditional methods (Tripathi and Bhardwaj 2004). Eisenia foetida is employed across the world for this objective as it is most prevalent, can withstand a broad range of temperature, and can survive in waste with good moisture content (Dominguez et  al. 1997) and Reinecke et  al. 1992). Other commonly used worms are Eudrilus eugeniae and Perionyx excavates. Eudrilus eugeniae may be appropriately usable in the areas with less variation in temperature (tropical areas).

5.2 Organic Matter and Earthworms in the Soil Earthworms consume more organic matter as compared to the other soil animals. Firstly, they play a role in the breakdown of organic matter, and then further decomposition is carried out which results in the liberation of nutrients that are present in organic matter, in plant-available form, and are also recycled. The partially decomposed organic matter is consumed by the earthworms and is fragmented and carried to sub-surface layers which results in the dispersion of organic matter through the soil. The decomposed organic matter is excreted by the earthworms in the form of castings which are rich in nutrients and are more soluble in water. The excreted material, i.e., castings, is present on the surface of the soil in the burrows formed by

5.4  Soil Phosphorus and Earthworms

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earthworms or beneath the soil surface in free space (Edwards and Bohlen 1996). Earthworms are the principal soil micro-organisms that are responsible for organic matter breakdown, dispersion, and its conversion to nutrients in plant-available form.

5.3 Soil Nitrogen and Earthworms The nitrogen-fixing bacteria is present in earthworm gut as well as casts. Earthworms add a sufficient amount of nitrogen into the soil through the mineralization of organic matter. As a result of increased nitrification in castings of earthworms, the nitrogen status of the soil is enhanced. The biomass of earthworms is also responsible for the addition of considerable amounts of nitrogen in the terrestrial ecosystem (Chauhan 2013). The dead tissues of L. terrestris are responsible for returning 60–70 kg N/ha/year in woodland in England (Edwards and Bohlen 1996). He also expressed that 70% of nitrogen present in earthworm tissues is mineralized within 10–20 days. The decomposition of earthworm tissue is a quick process and hence mineralization of nitrogen takes place rapidly.

5.4 Soil Phosphorus and Earthworms Phosphorus is the second most important essential nutrient and plays a vital role in the plant life cycle after nitrogen. It is responsible for energy transfer and storage in metabolic reactions taking place in living cells. Phosphorus is also known to encourage the early vegetative growth and accountable for early maturity in grain crops (Chauhan 2013). Phosphorus is not easily available to the plants as its solubility in water and mobility in the soil are low as compared to other major nutrients. The reason for the low availability of phosphorus in the soil is pH of the soil, ion-­ antagonism, and metal concentration (Fe, Al, Ca) that can co-precipitate with phosphorus ions. Earthworm activities are important in phosphorus cycling as it was noticed by Pitkänen and Nuutinen (1998) through beneficial interactions between phosphorus content of soil and earthworms. Earthworm cast is a rich source of available phosphorus that may be because of the enhanced activity of phosphatase in casts (Satchell 1967). According to Kuczak et al. (2006), the reason behind the enhanced phosphorus in castings of earthworm may be because of: (a) raised pH of earthworm intestinal tract (6.8 and 6 for an anterior and posterior part and 5 to 5.4 for the soil, respectively) (Chauhan 2013), (b) in the gut of earthworm, mucus extensive extent can act as a barriers and wrestle for P sorbing places and hence enhance soluble P, (c) enhanced activity of micro-organisms at the time of digestion process (Chauhan 2013). With the ingestion of soil by earthworms and intensive blending of soil in the earthworm intestinal tract, the chemical forms as well as the concentrations of phosphorus can be modified. The inorganic phosphorus releases four times quickly as compared to the soil surface (Sharpley and Syers 1976).

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Vermicomposting is a mesophilic bio-oxidative process in which detritivorous earthworms interact intensively with micro-organisms and soil invertebrates within the decomposer community, strongly affecting decomposition processes, accelerating the stabilization of organic matter, and greatly modifying its physical and bio-­ chemical properties (Edwards and Bohlen 1996; Dominguez 2004; Edwards and Arancon 2004). Vermicomposting includes combined action of earthworms and micro-organisms. The reason of bio-chemical decomposition of organic matter are the enzymes that are originated by the micro-organisms. Earthworms are involved in the ambiguous triggering of the microbial population through ingestion and fragmentation of fresh organic matter, as a result the surface area of organic particles is increased which enhances the microbial colonization, hence microbial activity is increased. In the system of vermicomposting, the disintegrating organic matter is a heterogenous matrix of organic material with contrasting qualities. Earthworms play the role of mechanical blenders and by crushing and grinding the organic matter they alter its physical and chemical status. The physical characteristics that are influenced by earthworms comprise stability, porosity, and aggregation, whereas chemical and biological properties that are influenced by earthworms include decomposition rates of organic matter, nutrient cycling (mainly N and P), chemical forms of nutrients in the soil and their supply to plants. Earthworms also influence the pH and organic matter dynamics. Vermicompost is peat-like material which is finely divided and acquires high water-holding capacity and porosity but low C:N ratio. Nutrients in the vermicompost are in readily available form and are easily taken up by the plants. The availability of inorganic nutrients especially ammonia and nitrates and also magnesium, calcium, potassium is raised in it due to high rates of mineralization. It also consists of plant growth hormones originated by micro-organisms and plant growth regulators as humates. The process of vermicomposting proceeds through two different stages including the action of earthworms. Initially, earthworms process wastes, thereby altering physical conditions and microbial confirmation, called the agile stage. The second stage is marked by the movement of earthworms toward fresher layers of undigested waste. At the same time decaying of earthworm-processed waste is taken over by the microbes. Among the various remarkable chemical traits of vermicomposts, it has been reported by Edwards and Burrows (1988) that vermicompost prepared by using animal waste sources comprises high mineral elements as compared to commercial plant growth media.

5.5 Heavy Metals and Vermicomposting Vermicomposting is an eco-friendly technique that can be employed to reduce the toxicity in the environment. It has been examined that the heavy metal concentrations in the feeding material are reduced heavily with the vermicomposting process as compared to other normal composting techniques (Goswami et al. 2017). The feeding material that possesses heavy concentrations of heavy metals when used for vermicomposting results in the worm cast with a reduced level of heavy metals.

References

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This is accredited to the accumulation of heavy metals in worm tissues (Sahariah et al. 2019). The concentration of heavy metals in vermicompost varies according to the feed used (Abu et al. 2015). Vermicomposting using four treatments: cow dung (CD): spent mushroom compost (SMC), CD:2SMC, goat manure (GM): SMC, and GM:2SMC spiked with 2 L landfill leachate each for 75 days leads to huge removal of heavy metals. 90% of cadmium (Cd), 80% of lead (Pb) were flushed out in all treatments. At the same, the concentration of copper (Cu) enhanced in CD: SMC II and GM: SMC I. The zinc (Zn) concentration is also increased but alone in GM: SMC I (15.01%) (Piya et al. 2018). According to Lukkari et al. (2006) the per cent increase in Cu and Zn is because of bindings of heavy metal to organic matter.

References Abu A, May C, Zalina N, Abdullah N (2015) Effect on heavy metals concentration from vermiconversion of agro-waste mixed with landfill leachate. Waste Manag 38:431–435 Bhat JV, Khambata P (1996) Role of earthworms in agriculture. Publication of Indian Council of Agriculture Research (ICAR), New Delhi Bhattacharya SS, Chattopadhyay GN (2002) Increasing bioavailability of phosphorus from fly ash through vermicomposting. J Environ Qual 31(6):2116–2119 Bhawalkar VV, Bhawalkar VS (1993) Vermiculture: the bionutrition system: national seminar on indigenous technology for sustainable agriculture. I.A.R.I, New Delhi Chauhan HK (2013) Effect of different combinations of animal dung and agro wastes on the reproduction and development of earthworm Eisenia fetida. Thesis awarded, Department of Zoology, Deen Dayal Upadhyaya Gorakhpur University, Gorakhpur, India Dominguez J (2004) State-of-the art and new perspectives on vermicomposting research. In: Edwards CA (ed) Earthworm ecology, 2nd edn. CRC Press, Boca Raton, pp 401–424. https:// doi.org/10.1201/9781420039719.ch20 Dominguez J, Edwards CA, Subler S (1997) A comparison of vermicomposting and composting. Biocycle 38:57–59 Edwards CA, Arancon N (2004) Vermicompost suppresses plant pests and disease attacks. Rednova News Edwards CA, Bohlen PJ (1996) Biology and ecology of earthworms, vol 3, 3rd edn. Chapman & Hall, London Edwards CA, Burrows I (1988) The potential of earthworm composts as plant growth media. In: Edwards CA, Neuhauser EF (eds) Earthworms in waste and environmental management. SPB Academic Publishing, The Hague, pp 211–219 Goswami L, Nath A, Sutradhar S, Bhattacharya SS, Kalamdhad A, Vellingiri K, Kim K-H (2017) Application of drum compost and vermicompost to improve soil health, growth, and yield parameters for tomato and cabbage plants. J Environ Manag 200:243–252 Kuczak CN, Fernandes ECM, Lehmann J, Rondon MA, Luizão FJ (2006) Inorganic and organic phosphorus pools in earthworm casts (Glossoscolecidae) and a Brazilian rainforest Oxisol. Soil Biol Biochem 38:553–560. https://doi.org/10.1016/j.soilbio.2005.06.007 Lukkari T, Teno S, Vaisanen A, Haimi J (2006) Effect of earthworms on decomposition and metal availability in contaminated soil: microcosm studies of populations with different exposure histories. Soil Biol Biochem 38:359–370 Padmavathiamma P, Li L, Kumari U (2008) An experimental study of vermi-biowaste composting for agricultural soil improvement. Bioresour Technol 99:1672–1681. https://doi.org/10.1016/j. biortech.2007.04.028

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Pitkänen J, Nuutinen V (1998) Earthworm contribution to infiltration and surface runoff after 15 years of different soil management. Appl Soil Ecol 9:411–415. https://doi.org/10.1016/ S0929-­1393(98)00098-­5 Piya S, Shrestha I, Gauchan D, Lamichhane J (2018) Vermicomposting in organic agriculture: influence on the soil nutrients and plant growth. Int J Res 5:1055–1063 Reinecke J, Viljioen SA, Saayman RJ (1992) The suitability of Eudrilus eugeniae, Perionyx excavatus and Eisenia fetida (Oligochaete) for vermicomposting in southern Africa in terms of their temperature requirements. Soil Biol Biochemist 24:1295–1307 Sahariah B, Das S, Goswami L, Paul S, Bhattacharyya P, Bhattacharya SS (2019) An avenue for replacement of chemical fertilization under rice-rice cropping pattern: sustaining soil health and organic C pool via MSW-based vermicomposts. Arch Agron Soil Sci 66(10):1449–1465 Satchell JE (1967) Lumbricidae. In: Burges A, Raw F (eds) Soil biology. Academic Press, London, pp 259–322 Senapati BK, Julka JM (1993) Selection of suitable vermicomposting species under Indian conditions. In: Earthworm resources and vermiculture. Zoological Survey of India, Calcutta, pp 113–115 Sharpley AN, Syers JK (1976) Potential role of earthworm casts for the phosphorous enrichment of runoff waters. Soil Biol Biochem 8:341–346. https://doi.org/10.1016/0038-­0717(76)90030-­4 Tripathi G, Bhardwaj P (2004) Comparative studies on biomass production, life cycles and composting efficiency of Eisenia fetida (Savigny) and Lampito mauritii (Kinberg). Bioresour Technol 92(3):275–283

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Different Sources of Vermicompost: Vermicomposting from Household Waste—Vermicomposting from Farm Waste

6.1 Different Sources of Vermicompost Vermicomposting mainly involves the bio-degradation activity of earthworms to maintain nutrient flow from one system to another. Vermicompost unit generally contains bedding and food materials for earthworms. Bedding material control moist level, provide food to worms, and give a good environment for breeding. Bedding material must have the following characteristics: • High absorbency: Earthworms depend on a moist environment to facilitate respiration through their skin. Any drying out of their skin can be fatal. Therefore, the bedding material must possess the ability to effectively absorb and retain water to ensure the well-being of the worms. • Optimal aeration: Worms, like humans, require oxygen for survival. If the bedding material is initially too dense or compacts tightly, it can impede or even eliminate the flow of air. Various factors influence the overall porosity of the bedding, including particle size, shape, texture, and structural strength. Collectively, these factors are referred to as the material’s bulking potential within this context. This characteristic is crucial for maintaining proper aeration for the worms. • Low protein or nitrogen content (high Carbon: Nitrogen ratio): While earthworms do consume their bedding as it undergoes decomposition, it is essential that this process occurs gradually. Elevated levels of protein and nitrogen can lead to swift degradation, causing an increase in temperature that creates unfavorable and potentially lethal conditions. It is worth noting that controlled heating can be a safe occurrence within the food layers of a vermiculture or vermicomposting system, but it should be avoided within the bedding material. Commonly used bedding material are given in Table 6.1.

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_6

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Table 6.1  Common bedding material used Bedding material Horse manure Straw—General Corn stalks Leaves (dry, loose) Shrub trimmings Sawdust Newspaper Peat moss

Absorbency Medium-good Poor Poor Poor-medium Poor Poor-medium Good Good

Bulking Pot. Good Medium-good Good Poor-medium Good Poor-medium Medium Medium

C:N ratio 22–56 48–150 60–73 40–80 53 142–750 170 58

Source: www.atlanticcountrycomposting.com Table 6.2  Different sources and earthworm species used in vermicomposting Organic waste Animal waste/manure Rice husk Soybean husk Sugarcane bagasse Temple waste (flowers)

Earthworm species used Eisenia fetida Eudrilus eugeniae Eudrilus eugeniae Eudrilus eugeniae Eudrilus eugeniae

Water hyacinth

Eudrilus eugeniae and Perionyx excavatus Eisenia fetida Eisenia fetida

Guar gum Mango leaves Vegetable market solids Herbal industry waste and cow dung Food industry Sewage sludge and waste paper Waste coffee Household solid waste and cow dung Wood waste

References Gark et al. (2005) Lim et al. (2012) Lim et al. (2011) Palsania et al. (2008) Gurav and Pathade (2011) Gupta et al. (2007)

Eisenia fetida Eisenia fetida

Suthar (2007) Talashilkar et al. (1999) Suthar (2009) Singh and Suthar (2012) Garg et al. (2012) Ndegwa et al. (2000)

Eisenia fetida Eisenia fetida

Liu and Price (2011) Garg and Gupta (2011)

Drawida willis

Shweta (2011)

Eisenia fetida Eudrilus eugeniae

Worm food material include animal manures, food industry wastes, municipal solid wastes, biogas sludge, and bagasse from sugarcane industry, etc. Commonly used wastes/sources and earthworm species used in vermicomposting are given in Table 6.2. These sources of vermicompost have specific characteristics, which make it highly useful or toxic to the worms. Therefore, the advantages and disadvantages of different sources of vermicompost are given in Table 6.3.

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6.1  Different Sources of Vermicompost Table 6.3  Advantages and disadvantages of different sources of vermicompost Wastes Cattle manure

Advantages Good nutrition; natural food

Poultry manure

High N content results in good nutrition Good nutrition; produce excellent vermicompost

Pig manure

Sheep/goat manure

Good nutrition

Rabbit manure

N content second to poultry manure; good nutrition with vitamins and minerals Higher N content

Legume hays

Grains

Excellent, balanced nutrition, no odor

Gliricidia stem and tobacco leaves Kitchen waste (peels, fresh food etc.)

Good nutrition source

Excellent nutrition, good moisture content

Disadvantages Weed seeds make pre-composting necessary High protein levels can be dangerous to worms Usually in liquid form, must be dewatered or use highly absorbent bedding It is considered “hot” manure It has stinky smell and contribute much to greenhouse gases emission (CH4 & N2O) Require pre-­ composting (weed seeds) Must be leached prior to use because of high urine content

Characteristics Partially decomposed ready for consumption by worms

Moisture level not as high as other feeds, require more input More expensive to use; low moisture content; hard to digest and slow to break down Not suitable for multiplication of earthworms

Best to use in mixture with manures

Depending on source High N can result in overheating Meat and high fat waste create anaerobic conditions and odors, attract pests; require pre-composting

Gaddie and Douglas (1975) suggest that poultry manure is not suitable for worms because it is so “hot” In Hong Kong, Chan and Griffiths (1988) reported that worms (Eisenia fetida) fed untreated pig manure died within 24 h, but pre-composted pig manure supplemented with 4% calcium sulfate and washed before feeding, are good for worms

Use with right additives to increase C:N ratio Ideal worm feed (Gaddie and Douglas 1975) after drenching of urine

Worms consume grains but cannot digest tougher kernels, resulting in sudden overheating

Perhaps the alkaloids and other principal compounds present in these leaves may affect the survival of earthworms Some food wastes are preferred over others; Coffee grounds are attractive to worms; garlic, onion, citrus peels, dairy products, fish, and eggshells are not attractive to worms; root vegetables (e.g., potato culls) resist degradation and require a long time to be consumed. Non-vegetarian waste like bones are difficult to digest

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6.2 Vermicomposting from Household Waste 6.2.1 Method For household vermicomposting, a wide range of containers are available commercially, or one can use adapted containers such as repurposed plastic containers, wooden boxes, Styrofoam containers, or metal containers. However, it is essential for these containers to have holes or mesh for proper aeration. Adhikary (2012) outlines a method for household vermicomposting as follows: To start, a wooden box measuring 45 × 30 × 45 cm or an earthen/plastic container with a broad base and drainage holes should be chosen. At the bottom of the wooden box, a plastic sheet with small holes is placed. Within the box, a 3 cm layer of soil and a 5 cm layer of coconut fiber are added to aid in draining excess moisture. On top of this, a thin layer of compost containing the worm inoculum is placed. Typically, about 250 worms are sufficient for this size of the box. Vegetable wastes are then added daily in layers on top of the inoculum. The top of the box is covered with a piece of gunny bag to provide dim light inside the box. Once the box is full, it is left undisturbed for a week. When the compost appears to be ready, the box is exposed to light for 2–3 h, prompting the worms to move down to the lowermost layer of coconut fiber. The composted materials are then carefully removed starting from the top of the box, progressing downwards, and sieved for use in urban, intensive horticultural, or agricultural systems.

6.3 Vermicomposting from Farm Waste 6.3.1 Methods • Bin composting: Plastic or wooden containers with perforated walls having 45 cm × 60 cm × 20 cm size.

• Pits below the ground: Pit 1  m deep and 1.5  m wide. The length varies as required.

6.3  Vermicomposting from Farm Waste

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• Heaping above ground: The process begins by spreading the waste material on a polythene sheet placed on the ground, followed by covering of cattle dung. The resulting pile measures approximately 2 m wide at the base, 1.5 m in height, and 2 m in length. In a study conducted by Sunitha et al. (1997), the effectiveness of two methods for preparing vermicompost, namely the pit and heap methods, was compared. In the heap method, there was a notable increase in the earthworm population, with a 21-fold rise in Eudrilus eugeniae compared to a 17-fold increase observed in the pit method. Additionally, biomass production was significantly higher in the heap method, showing a 46-fold increase compared to the 31-fold increase observed in the pit method. Consequently, the production of vermicompost was also greater in the heap method, yielding 51 kg, as opposed to the 40 kg obtained using the pit method. • Pit/tank above ground: Various tank materials, including regular bricks, hollow bricks, shabaz stones, asbestos sheets, and locally sourced rocks, were assessed for the preparation of vermicompost. These tanks can be constructed with dimensions tailored to specific operational needs. Tank configurations could include 4.5 m length,1.5 m width, and 0.9 m height, or alternatively, 1 m length, 1.5 m width, and 0.9 m depth. In the case of commercial bio-digesters, they typically incorporate a partition wall with small holes to facilitate the easy movement of earthworms from one tank to another. • Cement rings: Vermicompost can also be prepared above the ground by using cement rings. Ring should be 90 cm in diameter and 30 cm in height.

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• Commercial method: ICRISAT has developed a commercial vermicomposting model comprising four chambers enclosed by walls measuring 1.5 m in width, 4.5 m in length, and 0.9 m in height. These chamber walls are constructed from diverse materials, including regular bricks, hollow bricks, shabaz stones, asbestos sheets, and locally sourced rocks. Within this model, partition walls feature small holes to enable the convenient movement of earthworms from one chamber to the next. To efficiently manage excess water, outlets are thoughtfully positioned at one corner of each chamber, designed with a slight slope to facilitate the collection of surplus water. This collected water can be reused at a later time or applied as earthworm leachate for crop cultivation. The four chambers are sequentially filled with plant residues, one after another. The initial chamber is systematically filled, layer by layer, with a combination of plant residues and cow dung. Subsequently, earthworms are introduced into this chamber. Following this, the second chamber is filled in a similar layered manner. As the contents in the first chamber undergo processing, the earthworms naturally transition to the second chamber, which has already been prepared and filled. This streamlined approach simplifies the harvesting of decomposed material from the first chamber and also reduces the labor required for both harvesting and introducing earthworms. Overall, this technology not only minimizes labor costs but also conserves water and time. According to Adhikary (2012), following method is used for farm waste vermicomposting: To create composting pits, dimensions of 2.5  m in length, 1  m in width, and 0.3 m in depth are typically employed. These pits are situated within thatched sheds, leaving their sides open. To ensure proper aeration and drainage of excess water, the pit bottom and sides are solidified through compaction using a wooden mallet. At the base of the pit, a layer of coconut husk, concave side facing upward, is spread. This layer is moistened, and on top of it, a mixture of bio-waste and cow dung in an 8:1 ratio is applied, extending to a height of 30 cm above ground level. Water is sprinkled daily over this layer. After a period of 7–10 days, during which the waste undergoes partial decomposition, earthworms are introduced into the pit, typically at a rate of 500–1000 worms per pit. The pit is then covered with jute bags. To maintain optimal conditions, the moisture level is controlled at 40%–50%, and the population density of worms is managed within the pit. Additionally, the temperature range of 20–30 °C is maintained by periodic water sprinkling. Worms may aestivate at higher temperatures and hibernate at lower temperatures. Once the compost reaches maturity, it is extracted from the pit along with the worms and placed in a shaded area with ample light. The worms naturally migrate to the bottom of the compost heap. After 1 or 2 days, the top layer of compost is harvested, while any undecomposed residues are returned to the pit, along with the worms, for further composting.

6.4  Different Sources and Preparation of Vermicompost

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6.4 Different Sources and Preparation of Vermicompost Different substrate sources are used to convert it into vermicompost. These sources are leguminous crops, neem leaves, weeds, rice straw, wheat straw, maize straw, vegetable crops, cow dung, etc. Bhuvaneshwari et al. (2019) suggested various sustainable techniques such as composting, biochar production, and mechanization that can help to curtain the issue of crop residue burning and reserving the nutrients in the soil that are present in the crop residues. Rorat and Vandenbulcke (2019) remarked that vermicomposting is an economic concept that results in transferring of different organic waste (domestic and industrial) into renewable energy sources or “biosoils” and its beneficial properties make it an alluring product for agriculture, gardening, and remediation of polluted areas. Indoria et  al. (2018) examined many different sources of soil organic amendments that possess astounding potential to ameliorate soil productivity and soil organic matter status and rejuvenate and magnify the dying total factor productivity of Indian soils. They highlighted the two best strategies—Composting and Vermicomposting, for the conversion of biomass of available alternative organic amendment sources to plant-rich products. Basha and Elgendy (2018) observed that vermicomposting is a promising technique to solve the problem of green waste accumulation and municipal solid waste. They concluded that vermicompost other than efficient economic substitute to inorganic fertilizer can also be used in land reclamation, removal of heavy metals from different waste, reducing pathogen, adjusting the land biology, and structure for better planting and germination. Islam et al. (2018) experimented by composting cow dung and crop residue and analyzed that the component ratios of output fertilizer were suitable for agricultural lands. Manyuchi and Phiri (2013) investigated that vermicompost and vermiwash obtained from diverse wastes inclusive of animal, plant, pharmaceutical, food waste, and sewage waste were rich in nitrogen, phosphorus, and potassium. Barik et al. (2010) studied the vermicomposting process by using locally available agricultural wastes and animal manure and concluded that vermicompost prepared from a mixture of crop residues amended with cow dung show higher nutrient content. They recorded that cereal and leguminous wastes, tree leaves, weeds, and the substrate containing 1–5% leguminous leaves are suitable for vermicomposting. Taheri Rahimabadi et  al. (2018) performed a field experiment to evaluate the influence of cow manure and its vermicomposting on enhancement of yield and quality of rice grain. They recommended the mixed application of manure and vermicompost, which leads to raised milling percentage and qualitative traits of grain, culminating in elevated nutritional value and yield of grains. El-Mashad et al. (2003) reported that two major issues of unused agricultural wastes are rice straw and cattle and buffalo manure. They stated that the usage of agricultural wastes for the formation of compost and energy in association with using solar energy will save fossil fuels and result in the advancement of general life quality and health conditions in the villages.

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Ramnarain et al. (2019) experimented on the preparation of vermicompost using dry grass clippings, rice straw, and cow manure with three treatments T1 (2 kg of rice straw + 10 kg of cow dung), T2 (10 kg of cow manure + 1 kg of rice straw + 1 kg of grass), and T3 (2 kg of grass + 10 kg of cow dung) and concluded that the combination of rice straw and grass has the highest rate of vermicompost production. Shak et al. (2014) demonstrated that rice straw as a feedstock support healthier growth and reproduction of earthworms than rice husk and further examined that rice straw mixed with two parts of cow dung (1RS:2CD) showed best combinations of nutrient results as well as the growth of Eudrilus eugeniae. Aslam et al. (2019) used different combinations of substrates, viz. cow dung, paper waste, and rice straw and reported that applying cow dung vermicompost coupled with recommended NPK enhanced crop yield, soil health, lowered insect (aphid) infestation and strengthen zinc and iron content of grain in wheat (Triticum aestivum L.). Nguyen and Nguyen (2018) recommended that the quality of cow dung and rice straw compost can be increased by adding cow urine into it. They assessed that the application of cow urine results in a significant increase in nitrogen and phosphorus content and shortened the composting period. Das (2015) prepared the compost from rice straw and rice straw-rice husk mixture in 1:1 (w/w) and concluded that the compost prepared from only rice straw contained a high amount of available nitrogen, available phosphorus and slightly high C/N ratio. Sanasam and Talukdar (2017) observed that aerobic composting of a mixture of municipal waste (MW) with cow dung (CD) and rice straw (RS) and inoculation with earthworm Eisenia fetida, produced high-quality manure with higher nutrient content, a higher population of beneficial bacteria and reduced level of pathogenic bacteria. Indrajeet and Singh (2010) investigated that waste materials with a high C/N ratio when mixed with nitrogen-­ rich leguminous green mulch to get the C/N ratio below 40:1, resulted in rapid decomposition and formation of vermicompost with excellent properties. He experimented by preparing five recipes using different combinations of cow dung, leaf litter, crop residues, and leguminous leaves and recorded that the vermicompost produced have increased nutritional status and a significant reduction in C/N ratio. Abul-Soud et al. (2009) studied the comparison between vermicomposting and conventional composting. Epigeic earthworms such as Lumbricus rubellus, Eisenia fetida, Perionyx excavatus, and Eudrilus eugeniae were used and were composted with different animal manure, kitchen wastes, and pre-composted agricultural wastes. They reported that the application of the vermicomposting results in raised N, P, and K content and reduced heavy metal content compared to conventional composting. Nayeem-Shah et  al. (2015) analyzed that rate of vermicomposting without pre-composting or another form of pre-treatment and fortification with animal dung, by using “pseudo discretized continuous operation protocol” and three epigeic species of earthworms Eudrilus eugeniae, Eisenia fetida, and Perionyx excavatus, which have no mortality, gain in body mass and good fecundity over time of reactor operation, and vermicompost can be made faster. Sivakumar et  al. (2009) composted parthenium plants and neem leaves. They assessed that composting the neem leaves irrespective of its pesticidal properties do not affect the growth of earthworms if used as a feeding material. Even though neem

References

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is known to kill nematodes, it has no harmful impact on growth and survival of earthworms and resulted in the normal level of castings and hatching success without mortality but in case of parthenium, the reduction of the growth and reproductive efficiency of earthworms beyond the amendment concentration of 75 g /500 g of cow dung had been observed. Gajalakshmi and Abbasi (2004a, b) confirmed that earthworms feed voraciously on neem compost and convert to an extent of 7% of the feed into vermicompost per day. They observed that worms grew faster and reproduce rapidly in neem fed vermireactors as compared to the reactors fed with mango leaf litter. Juniarso et al. (2018) showed that the application of neem compost @ 15 ton/ha in organic paddy field resulted in raised soil organic matter, soil CEC, total N, available N and K, P uptake, plant height, number of tiller, and rice productivity. Farid et al. (2011) conducted a field experiment to study the combined effect of cow dung (CD), poultry manure (PM), dhaincha (DH), and chemical fertilizers using different combinations to access the effect of these combinations on the yield of rice (BRRI dhan 41) and concluded that the grain and straw yields as well as yield attributing parameters such as plant height, number of effective tillers per hill, number of field grains per panicle, and panicle length were significantly influenced due to different treatments. They also measured that the relative performance of organic manures was in the order of PM > DH > CD. Indrajeet et al. (2010) made the vermicompost using farm garbage. Five types of recipes were prepared by a different combination of leaf litter, cow dung, babul leaves, bean leaves, sawdust, dhaincha leaves, and wheat straw and found that there were about 74–96%, 20–24%, 43–153% increase in N, P, K content, respectively, and great reduction in C/N ratio about 59%–69% and electrical conductivity about 32.6%. Parry et al. (2014) recognize suitable additive that can help in improving the vermicomposting process. They achieved that 2:1 ratio of dung and leaves show a great level of decomposition followed by 1:2 ratio of dung and leaves and lower level of decomposition was found in 1:1 ratio of dung and leaves.

References Abul-Soud M, Hassanein MK, Ablmaaty SM, Medany M, Abu-Hadid AF (2009) Vermiculture and vermicomposting technologies use in sustainable agriculture in Egypt. J Agric Res 87:1 Adhikary S (2012) Vermicompost, the story of organic gold: a review. Agric Sci 3(7):905–917 Aslam Z, Bashir S, Hassan W, Belliturk K, Ahmad N, Niazi NK, Khan A, Khan MI, Chen Z, Maitah M (2019) Unveiling the efficiency of vermicompost derived from different biowastes on wheat (Triticum aestivum L.) plant growth and soil health. Agronomy 9:791 Barik T, Gulati JML, Garnayak LM, Bastia DK (2010) Production of vermicompost from agricultural wastes—a review. Agric Rev 31:172–183 Basha M, Elgendy AS (2018) Vermicomposting of organic waste: literature review. http://uest. ntua.gr/naxos2018/proceedings/pdf/109_NAXOS2018_Basha_etal.pdf Bhuvaneshwari S, Hettiarachchi H, Meegoda JN (2019) Crop residue burning in India: policy challenges and potential solutions. Int J Environ Res Public Health 16:832 Chan PLS, Griffiths DA (1988) The vermicomposting of pre-treated pig manure. Biol Wastes 24:57–69

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Das PK (2015) Compost preparation technique standardization for raw material mixture of rice straw and rice husk in bulk amount. Indian For 141:1117–1123 El-Mashad HM, Van Loon WK, Zeeman G, Bot GP, Lettinga G (2003) Reuse potential of agricultural wastes in semi-arid regions: Egypt as a case study. Rev Environ Sci Biotechnol 2:53–66 Farid MS, Mamun MAA, Matin MA, Jahiruddin M (2011) Combined effect of cow dung, poultry manure, dhaincha and fertilizers on the growth and yield of rice. J Agro Environ 5:51–54 Gaddie RE, Douglas DE (1975) Earthworms for ecology and profit, Scientific Earthworm Farming, vol 1. Bookworm Publishing Company, Ontario, p 175 Gajalakshmi S, Abbasi SA (2004a) Earthworms and vermicomposting. Indian J Biotechnol 3:486–494 Gajalakshmi S, Abbasi SA (2004b) Neem leaves as a source of fertilizer-cum-pesticide vermicompost. Bioresour Technol 92:291–296 Garg VK, Gupta R (2011) Effect of temperature variations on vermicomposting of household solid waste and fecundity of Eisenia foetida. Biorem J 15(3):165–172 Garg VK, Suthar S, Yadav A (2012) Management of food industry waste employing vermicompost technology. Bioresour Technol 126:437–443 Gark VK, Chand SA, Yadav A (2005) Growth and reproduction of Eisenia foetida in various animal wastes during vermicomposting. Appl Ecol Environ Res 3(2):51–59 Gupta R, Mutiyar PK, Rawat NK, Saini MS, Garg VK (2007) Development of a water hyacinth based vermireactor using an epigeic earthworm Eisenia foetida. Bioresour Technol 98:2605–2610 Gurav MV, Pathade GR (2011) Production of vermicompost from temple waste (Nirmalya): a case study. Univers J Environ Res Technol 1(2):182–192 Indoria AK, Sharma KL, Reddy KS, Srinivasarao C, Srinivas K, Balloli SS, Osman M, Prathiba G, Raju NS (2018) Alternative sources of soil organic amendments for sustaining soil health and crop productivity in India—impacts, potential availability, constraints and future strategies. Curr Sci 115:2052 Indrajeet, Singh J (2010) Preparation of recipe for quality production of vermicompost. J Recent Adv Appl Sci 25:12–14 Indrajeet, Rai SN, Singh J (2010) Vermicomposting of farm garbage in different combinations. J Recent Adv Appl Sci 25:15–18 Islam MA, Talukder MSU, Islam MS, Hossian MS, Mostofa MG (2018) Recycling of organic wastes through the vermicomposting process of cow dung and crop residues. J Bangladesh Acad Sci 42:1–9 Juniarso S, Utami SNH, Purwanto BH, Devangsari IM (2018) The effect of cow manure and neem compost toward NPK uptake, soil respiration, and rice production in organic paddy field in Imogiri Bantul, Indonesia. IOP Conf Ser Earth Environ Sci 215(1):012026 Lim PN, Wu TY, Sim EYS, Lim SL (2011) The potential reuse of soybean husk as feedstock of Eudrilus eugeniae in vermicomposting. J Sci Food Agric 91:2637–2642 Lim SL, Wu TY, Sim EYS, Lim PN, Clarke C (2012) Biotransformation of rice husk into organic fertilizer through vermicomposting. Ecol Eng 41:60–64 Liu K, Price GW (2011) Evaluation of three composting systems for the management of spent coffee grounds. Bioresour Technol 102:7966–7947 Manyuchi MM, Phiri A (2013) Vermicomposting in solid waste management: a review. Int J Sci Eng Technol 2:1234–1242 Nayeem-Shah M, Gajalakshmi S, Abbasi SA (2015) Direct, rapid and sustainable vermicomposting of the leaf litter of neem (Azadirachtaindica). Appl Biochem Biotechnol 175:792–801 Ndegwa PM, Thompson SA, Das KC (2000) Effect of stocking density and feeding rate on vermicomposting of bio solids. Bioresour Technol 7:5–12 Nguyen TP, Nguyen TNQ (2018) Composting of cow manure and rice straw with cow urine and its influence on compost quality. J Viet Environ 9:61–66 Palsania J, Sharma R, Srivastava JK, Sharma D (2008) Effect of moisture content variation over kinetic reaction rate during vermicomposting process. Appl Ecol Environ Res 6(2):49–61

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Parry MA, Wani MG, Rather GM (2014) Stimulatory influence of some additives on vermicomposting by Eudriluseugeniae. Int J Eng Sci Invent 3:1–4 Ramnarain YI, Ansari AA, Ori L (2019) Vermicomposting of different organic materials using the epigeic earthworm Eisenia foetida. Int J Recycl Org Waste Agric 8:23–36 Rorat A, Vandenbulcke F (2019) Earthworms converting domestic and food industry wastes into biofertilizers. In: Prasad MNV, Favas PJDC, Vithanage M, Mohan SV (eds) Industrial municipal sludge. Butterworth-Heinemann, Oxford, pp 83–106 Sanasam SD, Talukdar NC (2017) Quality compost production from municipality biowaste in mix with rice straw, cow dung, and earthworm Eisenia foetida. Compost Sci Util 25:141–151 Shak KPY, Wu TY, Lim SL, Lee CA (2014) Sustainable reuse of rice residues as feedstocks in vermicomposting for organic fertilizer production. Environ Sci Pollut Res 21:1349–1359 Shweta RK (2011) Enhancement of wood waste decomposition by microbial inoculation prior to vermicomposting. Bioresour Technol 102:1475–1480 Singh D, Suthar S (2012) Vermicomposting of herbal pharmaceutical industry solid wastes. Ecol Eng 39:1–6 Sivakumar S, Kasthuri H, Prabha D, Senthilkumar P, Subbhuraam CV, Song YC (2009) Efficiency of composting parthenium plant and neem leaves in the presence and absence of an oligochaete, Eisenia foetida. Iran J Environ Health Sci Eng 6:201–208 Sunitha ND, Giraddi RS, Kulkami KA, Lingappa S (1997) Evaluation methods of vermicomposting under open field conditions. Karnataka J Agric Sci 10(4):987–990 Suthar S (2007) Vermicomposting potential of Perionyx sansibaricus (Perrier) in different waste materials. Bioresour Technol 98:1231–1237 Suthar S (2009) Vermicomposting of vegetable-market solid waste using Eisenia foetida: impact of bulking material on earthworm growth and decomposition rate. Ecol Eng 35:914–920 Taheri Rahimabadi E, Ansari MH, Razavi Nematollahi A (2018) Influence of cow manure and its vermicomposting on the improvement of grain yield and quality of rice (Oryza sativa L.) in field conditions. Appl Ecol Environ Res 16:97–110 Talashilkar SC, Bhangarath PP, Mehta VB (1999) Changes in chemical properties during composting of organic residues as influenced by earthworm activity. J Indian Soc Soil Sci 47:50–53

7

Preparation of Vermicompost

7.1 Introduction Vermicomposting represents an environmentally friendly approach to breaking down organic matter with the assistance of earthworms and beneficial micro-­organisms. To commence vermicomposting, one must carefully choose a suitable container or bin that provides adequate aeration and drainage. An initial layer of bedding material, such as shredded newspaper or coconut coir, is placed at the bottom. Earthworms are then introduced to the bedding, where they naturally burrow and integrate into the environment. Ongoing contributions of organic kitchen waste, garden waste, and compatible materials are made to the bin while avoiding substances such as meat, dairy, and oily foods. It is essential to uphold optimal conditions, including a temperature range of 55–77 °F and appropriate moisture levels. Periodically turning the compost helps ensure proper aeration. Once the vermicompost transforms into a dark, crumbly substance with a rich, earthy aroma, it is ready for harvest. This is accomplished by prompting the worms to migrate to one side of the bin. The resulting nutrient-rich vermicompost proves invaluable for enhancing soil quality and nourishing plants, promoting sustainability in gardening practices. Regular monitoring and adjustments are key to maintaining the continued effectiveness of the vermicomposting process.

7.2 Sequential Method of Composting The following steps are taken to prepare vermicompost. Stage 1: Stone, glass, plastics, and metals are separated from organic waste/waste and large bundles of organic waste are broken up into piles. Stage 2: Coarse organic residues such as leaves, plant stems, sugarcane residues are cut into small pieces of about 2–4 inches so that vermicompost could be prepared in lesser time. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_7

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Stage 3: To remove odor and unnecessary materials from the waste, it is spread in the sun in 1 foot thick surface layer to dry. Stage 4: Organic waste is mixed with cow dung and put in the pit for decomposition for 1  month. Water is sprinkled daily to maintain proper moisture content. Stage 5: To make compost, first 1 inch thick layer of sand is spread on the floor and then a layer of 3–4 inch thick crop residues is applied on it. Again, 18 inch thick layer of material obtained from step 4 is laid on it in such a way that its width becomes 40–45  inches. The length of the bed is determined by the available space. In this way, about 500 kg of organic waste is decomposed in a band of 10  feet length. The bed is kept semi-circular so that there is ample space for earthworms to regulate their activities and for air management in the bed. In this way, after making the bed, keep sprinkling water to maintain proper moisture content, then leave it for 2–3 days. Step 6: When the temperature is uniform in all parts of the bed, approximately 5000 earthworms/500 kg of residues are added in bed from one side in such a way that they could spread throughout the bed. Step 7: Cover the entire bed with a 3–4 inch thick layer of finely chopped residues. Under favorable conditions, earthworms spread all over the bed by itself. Mostly, earthworms could reach 2–3 inches deep in the bed and continue the decomposition process. Stage 8: Under favorable humidity, temperature and ventilated conditions, after 25 to 30 days, 3–4 inch thick compost accumulates on the upper surface of the bed. To separate it, the outer covering surface of the bed is removed from one side. This way, when earthworms go deep into the bed, the vermicompost can be easily separated from the bed and then the bed is covered with the residues as before and water is sprinkled to retain moisture. Stage 9: In about 5–7 days, another layer of 4–6 inch thick compost is formed. This is also separated like stage 8 and then water is sprinkled in the bed to retain moisture. Stage 10: After this, at intervals of 5–7 days, again under favorable conditions, a 4–6  inch thick layer of compost is formed, which is first separated like the ninth stage. In this way, about 80–85% of compost can be collected in 40–45 days. Stage 11: Eventually, some of the compost, earthworms and their eggs (cocoons) remain in the form of a small pile of compost. Therefore, it could be used as a source of earthworms in the second phase. In this way, the earthworms continue to repeat this process for the production of compost. Stage 12: From the collected vermicompost, earthworm eggs, juvenile earthworms and crop residues which are not eaten by earthworms are separated by 3–4 mesh shaped sieves. Stage 13: To remove excess moisture, compost is spread on the paved floor and it is collected when the humidity is around 30–40%. Step 14: Vermicompost is sealed and packed in plastic/HDPE bags so that it does not lose moisture.

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The preparation of vermicompost comprises five distinct stages. This process occurs within the mesophilic temperature range, typically ranging from 35 to 40 °C. The various phases involved in this procedure can be outlined as follows: 1. Initial Pre-composting Phase: In this stage, organic waste undergoes pre-­ composting for approximately 15  days before it is introduced to earthworms. During this phase, easily decomposable compounds are broken down, and any potentially harmful volatile substances are removed, which could pose a threat to earthworms. Pre-composting of the feedstock serves the purpose of reducing the material’s energy content, preventing excessive heating within the worm system. Feedstocks that undergo pre-composting for 10–14 days maintain an adequate nutritional value for the worms, while avoiding an excess of energy that could lead to heat generation (Nair et al. 2006). 2. Mesophilic phase: The partially decomposed waste material should be blend with 30% cattle dung, either by weight or volume. This mixture is then filled to the brim in the designated container or tub. It is crucial to maintain the moisture level at around 60%. If necessary, sprinkle water onto the material rather than pouring it. The selected earthworms are distributed uniformly over the prepared bed. For a space measuring 1 m in length, 1 m in width, and 0.5 m in height, approximately 1  kg of worms (equivalent to 1000 individuals) is required. Throughout this phase, earthworms perform their unique functions, which involve breaking down organic matter, integrating with soil particles, and promoting microbial activity. This process conditions the organic waste materials, ultimately leading to the production of valuable organic fertilizers. 3. Maturing and stabilization phase: During this phase of the vermicomposting process, earthworms contribute through a combination of physical/mechanical and biochemical actions. Their physical involvement includes breaking down organic substances, leading to fragmentation, which in turn increases the surface area available for further microbial colonization. On the biochemical front, the decomposition of organic matter occurs through enzymatic digestion. This process involves the enrichment of organic matter with nitrogen excrement and the transportation of both organic and inorganic materials. As the materials pass through the earthworm intestine, a rapid transformation occurs, converting locked-up minerals such as nitrogen, potassium, phosphorus, and calcium into more soluble and readily available forms for plants, compared to their original state. This transformation is facilitated by a variety of enzymes present in the digestive system of earthworms, as well as enzymes from certain types of ingested micro-organisms, including proteases, lipases, amylases, cellulases, and chitinases. These enzymes play a crucial role in breaking down cellulosic and proteinaceous materials found in organic waste. It is worth noting that earthworms appear to have established a mutualistic relationship with the micro-­ organisms they ingest, which aids in the decomposition of organic matter present in their food. Consequently, the final quality of vermicompost is the result of the collaborative efforts of earthworms and the micro-organisms involved in this intricate process.

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The following steps are involved in the process of vermicomposting Step 1: Gather waste materials, shred them, mechanically separate metals, glass, and ceramics, and store the organic waste. Step 2: The organic waste undergoes a pre-digestion process by combining it with a slurry made from cattle dung. This procedure partially digests the material, making it suitable for consumption by earthworms. It is important to note that cattle dung and biogas slurry can be used for this purpose after they have been dried. Using wet dung is not advisable for the production of vermicompost. Step 3: Creating the vermibed involves the use of a concrete base, which is essential for the vermicomposting process. The use of a concrete base prevents earthworms from escaping into the soil, and it also ensures that while watering the bed, all the soluble nutrients are retained in the soil along with the water. Step 4: Earthworm collection takes place after the vermicompost has been harvested. The composted material is sieved to separate the fully composted material from the partially composted material. The partially composted material is then returned to the vermibed for further processing. Step 5: The vermicompost is stored in a designated location or room. The storage area is carefully maintained to preserve moisture levels and create an environment conducive to the growth of beneficial micro-organisms.

7.3 Mechanism of Earthworm Action Earthworms play a pivotal role in waste decomposition through a multifaceted mechanism. They facilitate the proliferation of “beneficial decomposer aerobic bacteria” within the organic waste material. In addition, earthworms serve as aerators, grinders, crushers, chemical degraders, and biological stimulators in the decomposition process. Earthworms host a vast community of decomposer microbes within their gut, also known as bio-degraders. According to Edwards (1988), the number of bacteria and actinomycetes within the ingested material can increase by up to 1000 times as it passes through the earthworm’s digestive system. In a relatively short period, a population of around 15,000 earthworms can foster a microbial population numbering in the billions. Under favorable conditions, earthworms and micro-­ organisms engage in a symbiotic and synergistic relationship. This partnership accelerates and enhances the decomposition of organic matter within the waste material, further contributing to the vermicomposting process. Micro-organisms are responsible for breaking down cellulose found in food waste, grass clippings, and garden waste leaves. The ingested waste feed materials are finely pulverized, typically with the assistance of stones located in the earthworm’s muscular gizzard. This grinding process reduces the materials into tiny particles, typically measuring between 2 and 4 microns in size, before they are passed on to the intestine for enzymatic reactions. Both the gizzard and the intestine function as a kind of “bioreactor.” Within these digestive organs, earthworms secrete various enzymes, including proteases, lipases, amylases, cellulases, and chitinases.

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These enzymes play a pivotal role in facilitating the rapid bio-chemical conversion of the cellulose and proteinaceous components present in the organic waste materials. The final step in vermicomposting and the degradation of organic matter involves a process known as “humification.” During this phase, large organic particles are transformed into a complex, amorphous colloid containing phenolic materials. However, it is important to note that only approximately one-fourth of the organic matter is converted into humus.

7.4 Vermicomposting Systems 7.4.1 Windrow System This approach involves the creation of windrows that are placed under shade to prevent direct sunlight. The process commences by evenly spreading a layer of earthworms and bedding material on the ground or a suitable surface. The initial layer of a new windrow should have a height of 10–15 cm. To initiate the process, earthworms can be cultured in a production nursery or rectangular boxes before being introduced into the windrows. The earthworms gradually consume the feedstock from the bottom to the top of the bed. Continuous monitoring of the windrow is essential, and when indications of surface feeding become evident, an additional layer of feedstock measuring 7–10 cm can be incorporated. The use of excessively thick layers of feedstock is discouraged because it hinders the penetration of oxygen into the windrow. This can lead to earthworms migrating to the upper surface before the lower layers have undergone thorough digestion, resulting in anaerobic fermentation. To maintain the ideal moisture level of 80% within the windrow, center post sprinklers are employed for irrigation. As the process advances, the material on the top layer is removed to initiate a new row, while the material at the bottom has been converted into vermicompost. The new row can either be started in a fresh location or shifted longitudinally by approximately 20  feet. This relocation is achieved by depositing the worm-populated material beyond the end of the current row, extracting some vermicompost, and then transferring additional earthworms as needed. One challenge associated with this approach is the manual labor involved in the process. In cases, where the windrow is sufficiently wide, there may be the option to use a loader to extract some material from the top. However, the remaining material will still need to be manually forked off, as using a loader may push it over and off the opposite side of the row. Regardless of the method chosen, there is a risk of material rolling down the sides during the removal of the top layer, and extra care is essential to ensure that this material does not inadvertently mix with the finished product. Windrow systems are highly effective in locations where temperatures remain consistently suitable. When utilizing outdoor windrows, it is preferable to have them positioned beneath a shaded structure, ideally on a slightly raised concrete platform. In cases where no shade structure is available, or if the existing structure

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does not provide protection from rain, it is essential to have compost covers readily available for use during periods of heavy or frequent rainfall. Handling compost covers can be cumbersome and typically requires the assistance of two or more individuals. Moreover, if concrete is not accessible, an impermeable surface such as asphalt or specific types of clay should be in place to support the windrow system.

7.4.2 Wedge System This is a modified windrow system that optimizes space and simplifies the harvesting process by eliminating the need to separate earthworms from vermicompost. Organic wastes are applied in layers at 45 ͦ angle against an existing finished windrow. The piles can be created either indoors within a structure or outdoors, provided they are covered with tarpaulin or compost cover to prevent nutrient leaching. A front-end loader is used to establish a windrow that is 1.2 to 3 m wide and of an appropriate length. The process begins by spreading a layer of organic materials measuring 30–45 cm in thickness along the length of one end of the available space. Approximately 0.45 kg of earthworms are added per square meter of windrow surface area. Subsequent layers of organic materials, each measuring 5–7.5  cm in thickness, are added on a weekly basis, with more frequent additions preferred during colder seasons. As the windrow gradually reaches a depth of 2–3 feet, the earthworms in the initial windrow will naturally migrate toward the newly added feed. This lateral movement of the worms continues through the various windrows. After a period of 2–6 months, the initial windrow and each subsequent pile become ready for harvesting. An alternative approach to this method involves what’s known as a “migrating windrow.” In this technique, a row can initially begin as either a windrow or a layer and then gradually transform into a windrow. A loader is utilized to add organic material to one side of the row, ensuring it maintains a consistent height and length while gradually increasing width. After a certain duration, the loader is employed to extract vermicompost from the side opposite to the one being actively fed. Later on, the finished compost is harvested from this same opposite side once more. This process results in the row moving laterally, with feeding occurring along one side and harvesting along the other. It is worth noting that at any point in this process, the sides for feeding and harvesting can be interchanged to alter the direction of row migration.

7.4.3 Container System 7.4.3.1 Pits, Tanks, and Cement Rings The pits designed for vermicomposting typically have a depth of 1 m and a width of 1.5 m, with the length being adjustable according to specific needs. Various materials, including regular bricks, hollow bricks, asbestos sheets, and locally available rocks, have been assessed for their suitability in constructing tanks for vermicompost preparation. These tanks can be built with dimensions that are well-suited for

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the intended operations. Researchers at ICRISAT have examined tanks with dimensions measuring 1.5 m (5 feet) in width, 4.5 m (15 feet) in length, and 0.9 m (3 feet) in height. In commercial bio-digesters, there is typically a partition wall with small holes to facilitate the easy movement of earthworms from one tank to another (Nagavallemma et al. 2004). The cement rings can also be used to prepare the vermicompost above the ground, The size of the cement ring should be 30 cm in height and 90 cm in diameter.

7.4.3.2 Commercial Model The commercial vermicomposting model is structured with four chambers enclosed by a wall, with dimensions measuring 1.5 m in width, 4.5 m in length, and 0.9 m in height. The chambers walls can be constructed using various materials such as regular bricks, hollow bricks, asbestos sheets, and locally sourced rocks. Each chamber within this model is equipped with partition walls featuring small holes, which serve to facilitate the effortless movement of earthworms from one chamber to the next. Furthermore, there is a drainage outlet located at one corner of each chamber, designed with a slight slope to enable the collection of excess water. This collected water can be reused later or employed as earthworm leachate for crops. The four components of the tank are sequentially filled with plant residues. The initial chamber is meticulously layered with cow dung and plant material before introducing the earthworms. Subsequently, the second chamber is filled layer by layer. As the contents within the first chamber undergo processing, the earthworms naturally migrate to the second chamber, which has already been filled and prepared for their presence. This arrangement simplifies the harvesting of decomposed material from the first chamber and also streamlines the process by reducing the labor required for harvesting and introducing earthworms. This innovative approach not only lowers labor costs but also conserves water and time. 7.4.3.3 Beds or Bins Top-Fed Type A top-fed bed system operates within enclosed four walls, often located within a building. These bins are sufficiently spacious and sheltered from wind exposure, and if the feedstock used is relatively rich in nitrogen, the only insulation required may be a layer or “pillow” of insulation placed on top. These insulating materials can be bags or bales of straw. It is worth noting that these beds were primarily designed for vermiculture, focusing on earthworm cultivation rather than vermicomposting. The process of harvesting vermicompost is most effectively achieved by capitalizing on horizontal migration. To initiate harvesting, the operator discontinues feeding one of the beds for several weeks, allowing the earthworms ample time to complete the processing of that material and then migrate to the other beds in search of fresh feed. Once the “cured” bed is empty, it can be refilled with bedding material, after which feeding can resume. This rotation is carried out on a regular basis. In the case of larger beds, they can be emptied using a tractor instead of manual labor.

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Stacked Type One significant drawback of the bed or bin system is the requirement of substantial surface area. While this space requirement is also relevant to windrow and wedge systems, they are typically located outdoors, where space is less costly compared to indoor or covered spaces. Cultivating worms indoors or even within a shelter that lacks heating can be a costly endeavor, especially if the issue of space is not addressed. Stacked bins offer a solution to this space concern by introducing a vertical dimension to vermicomposting. The bins need to be of a manageable size so that they can be lifted, either manually or using a forklift, when they become full with wet material. Although they can be fed continuously, this involves regular handling. A more cost-effective approach is to employ a batch process. In this method, the material is pre-mixed and placed in the bin, earthworms are introduced, and the bin is stacked for a pre-determined duration before being emptied. This batch process is utilized by numerous professional vermicompost producers. The initial investment for establishing a stacked-bin system is substantial. It encompasses the expenses associated with acquiring a shelter, bins, equipment for mixing bedding and feed, and machinery for stacking the bins, like a forklift. On a smaller scale, these tasks can be carried out manually. Similar to batch windrow systems, a challenge arises during the harvesting phase, the earthworms become mixed in with the final product and must be separated. This separation process necessitates either the use of a dedicated harvester or an additional step in the procedure where the material is piled to enable the earthworms to migrate into fresh material.

7.4.4 Continuous Flow System This system design has become nearly universal in commercial vermicomposting operations of medium to large scale. In this setup, each system features a relatively deep top-fed container where the composting mass rests atop a raised floor constructed from widely spaced wire mesh. Earthworms are introduced into the system, and food waste is gradually added, with alternating layers of bedding material. Continuous feeding until the container is nearly filled. Typically, the worms migrate upwards through the layers of feedstock and bedding, and the vermicompost is collected from below. This is achieved by gently scraping or cutting a thin layer of the finished material located just above the wire mesh, using tools such as a rake or manually or hydraulically-operated blade. Continuous flow systems provide several advantages for medium to large-scale composting endeavors. They are relatively uncomplicated to build and operate, offering efficiency in terms of labor for both operation and the harvesting of finished material. These systems circumvent the necessity for costly equipment typically associated with technical “in-vessel” systems, as well as the labor-intensive processes of turning and screening windrowed material. It is worth noting that, despite the growing interest in continuous flow designs, windrows remain the most prevalent large-scale vermicomposting system in use. Continuous flow vermicomposting

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designs can be argued as the most effective systems available, offering substantial time and labor savings. However, it is essential to emphasize that regardless of efficiency or ease of operation, no design completely eliminates the need for vigilant monitoring and effective system management.

7.5 Maintaining Continuous Flow Continuous flow vermicomposting systems offer a steady supply of vermicompost that can be extracted from the system without causing disturbances to the earthworm activity or necessitating intricate or time-consuming harvesting techniques. Due to their operational efficiency, these system designs are gaining popularity in large-scale applications, approaching the level of popularity enjoyed by windrows. Nevertheless, similar to all vermicomposting systems, the continuous flow model presents certain challenges. To simplify some of the technical terminology, the earthworms commonly employed in vermicomposting are often referred to as “surface feeders.” There is a common assumption that earthworms are primarily active at or just beneath the surface. However, this presumption doesn’t always hold true. Earthworms respire oxygen and thrive in moist environments, requiring organic material to be in an active bacterial state before consuming it. In their natural habitat, this typically occurs in the top few inches of soil or in surface organic litter like fallen leaves. In any system that provides a free flow of oxygen, maintains monitored moisture levels, and offers an ample supply of decomposing organic matter, earthworms have the potential to distribute themselves throughout the material, unless the system is meticulously controlled. Consequently, earthworms can be found at various depths within continuous flow systems that fulfil their specific requirements. One of the benefits of the continuous flow design lies in its ease of extracting a continuous stream of vermicompost from the system. However, it is crucial not to initiate the harvesting of the finished material until the system is nearly filled with material. Many operators have discovered that, when combined with appropriate loading rates, maintaining a minimum material depth within the system, typically ranging between 12 and 18 inches, helps ensure that very few, if any, earthworms remain close to the bottom of the bed and inadvertently end up in the harvested vermicompost. Once the system is fully loaded, it is important to remove vermicompost at a rate that sustains a relatively consistent level of material within the system.

7.6 Feeding Rates The optimal loading rate, which refers to the rate at which raw feedstock can be introduced into a worm bed to encourage earthworms to concentrate near or at the surface, varies depending on factors such as the type of feedstock used, temperature, moisture levels, and the density of the worm population. To ensure proper loading

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rates, it is essential not to introduce new feedstock until the majority of the previously added material has undergone decomposition. Adding new feedstock prematurely can result in the accumulation of unprocessed material in the lower layers. Consequently, an adequate food supply remains deeper within the container rather than being concentrated immediately below the surface. This can lead to earthworms spreading throughout all available food areas. The movement of worms in the lower levels of flow-through systems often causes vermicompost to fall through the mesh floor before it has fully decomposed. Additionally, during harvesting, worms located in the lower material layers can drop through with the vermicompost. These worms then either require labor-intensive screening methods for separation or are lost from the system. Many operators of continuous flow systems have discovered that frequent additions of thin layers of feedstock (approximately 1 to 2 inches deep, evenly spread across the surface) yield the best outcomes. Sometimes, feedstock is mixed with bulking agents like compost, shredded leaves, cardboard, paper, or straw, or it can be covered with an equally thin layer of these materials. Paper-based products are favored as feedstock for earthworms because they offer a readily accessible and digestible source of carbon.

7.7 Excessive Heating Another challenge encountered in vermicomposting, regardless of its size, is the possibility of heat generation within the feedstock. Bacteria play a central role in breaking down raw organic matter, and in oxygen-rich environments, microbial activity leads to the production of water, carbon dioxide, and heat. When raw materials are introduced into the system, especially in substantial quantities, the mass can support the activity of billions of bacteria. This bacterial activity has the potential to generate significant amounts of heat, which can become trapped within the system. Even a small volume of raw material can undergo heating if it contains adequate energy to sustain high levels of bacterial activity. This propensity for heating adds complexity to the assessment of system loading rates. It is important to acknowledge that a worm bed may harbor thousands of different species of invertebrates and micro-organisms, all of which play crucial roles within the vermiculture ecosystem. Therefore, the determination of loading rates cannot rely solely on the needs or capacity of a single organism within the system. Bacterial activity can be just as influential as worm activity, especially considering that bacteria typically access the feedstock before the worms. Overfeeding (compared to the system’s design capacity, the nature of the feedstock, or the current level of system activity) can potentially lead to the production of enough heat to discourage worm activity. Unless there are possibilities for design adjustments, like the installation of fans to dissipate excess heat, it becomes necessary to reduce the loading rate to a level where heating is not a concern, even if this means providing less material than the worms are technically capable of processing.

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7.8 Method for Preparation of Vermicompost from Paddy Straw/Waste Maize Silage 1. For making vermicompost, cemented beds of dimensions 6 feet (length) × 3 feet (breadth) × 2 feet (height) should be constructed on leveled ground. The length of the bed may vary depending upon the space and resources. 2. The floor of the bed must be pucca floor to avoid seepage of vermin wash, feces, and urine of earthworms. 3. Firstly, lay the beds with 1 feet layer of paddy straw (chopped/unchopped)/waste 119 maize silage. Paddy straw/waste maize silage is well moistened by sprinkling water to maintain moisture up to 60–70%. 4. Then second layer of 4–5 days old animal dung is applied up to 2 feet depth. 5. Introduce 1  kg earthworms of species (Eisenia fetida) per 6  feet length. The quantity of worms may vary if the bed size varied from standard dimensions. 6. Two inch layer of soaked paddy straw is applied on the beds to avoid water loss through evaporation. 7. Turning after every week is required to maintain aeration for earthworms and decomposition of paddy straw. 8. Water spray is applied two times a day in summer and 2–3  days interval in winter. 9. Vermicompost will be ready after 60–70  days and 45  days of composting of paddy straw and waste maize silage, respectively.

7.9 Processing: Time and Acceleration 1. The time required to obtain vermicompost can vary depending on factors such as the worm population and the level of management. It is possible to produce vermicompost in as little as 5–6 weeks with high worm populations and vigilant management. Under favorable conditions, this can take 2–3 months (60–90 days). However, a more realistic estimate is 4–6 months when minimal management of the worm beds is practiced. 2. In high-volume flow-through systems, it has been observed that a marker, like a coin, placed on the bed’s surface typically reaches the bottom of the bed in approximately 60 days. 3. With a substantial worm population, kitchen waste or animal manure can decompose in as little as 4–6  weeks. If the material is intended for use in certified organic production systems, the required vermicomposting time for a batch system is extended to 4 months (16 weeks). 4. Without the addition of feed for 4  months, worm populations will noticeably decline. Worms are then extracted over a 1-month period, leaving a reduced population for up to 1 month before sieving the finished compost. This interval also allows time for additional worms to emerge from their cocoons.

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7.10 Maturity and Stability The quality of vermicompost is typically evaluated based on its stability and maturity. A well-prepared compost should exhibit a moist texture, loose soil, with a consistent and visually appealing appearance. Various physical, chemical, and biological transformations take place during the aerobic or vermicomposting processes. Several parameters have been proposed to gauge the maturity of compost, including C/N ratios, water-­ soluble carbon content, cation exchange capacity, CO2 levels, NH4-N/NO3-N ratio, organic carbon content, and humus content. However, one reliable indicator of compost maturity is the germination index (GI), which measures phototoxicity. Additionally, a coliform test can provide insights into pathogen reduction and overall compost quality.

7.11 Composting v/s Vermicomposting In contrast to traditional composting, vermiculture offers various applications, each capable of yielding different grades of end products, depending on factors like volume and time constraints: 1. Full Organic Waste Processing: This method results in the production of the highest-grade end product, known as worm casts. Worm casts typically contain significantly higher concentrations of essential nutrients compared to standard composted material. These worm casts are primarily used as a top-quality soil conditioner within the horticultural sector, rather than being utilized as bulk compost or plant bedding material. 2. Partial Organic Material Processing: This approach involves the partial processing of organic material, either to expedite the composting process or to create a product of superior quality compared to regular compost. 3. Odor Elimination: Vermiculture can effectively eliminate nuisance odors associated with the decomposition of organic matter, particularly in open-air composting methods that do not employ sealed “in-vessel” equipment. 4. Low Energy Requirements: Vermicomposting boasts minimal energy requirements when compared to existing waste disposal systems, and the associated processing costs are negligible. 5. Worm Breeding: While not a primary concern for a municipal composting facility, maintaining and breeding worms is essential, especially when large numbers of worms are necessary for satisfactory operation.

7.12 Acceleration Process 7.12.1 Organic Nutrients and Other Additives There are very few reports documenting successful utilization of organic nutrients or other additives to enhance the vermicomposting process. The application of Spirulina and Trichoderma as probiotic and microbial inoculants during the predecomposition phase was described as a means to achieve both qualitative and

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quantitative improvements in vermicomposting (Parray et al. 2014). Similarly, an organic nutrient known as Jeevamirtham, prepared using cow dung, urine, jaggery, and black gram flour can be used to enhance the earthworm’s performance and elevate the fertilizer value of vermicompost (Vasanthi et al. 2011).

7.12.2 Effective Micro-organisms (EM) EM is a multi-culture of co-existing anaerobic and aerobic beneficial micro-­organisms (Higa 1991). The major groups of the microbes present in EM are as follows: Lactic acid bacteria: Lactobacillus plantarum, L. casei, Streptococcus lactis. Photosynthetic bacteria: Rhodopseudomonas palustrus, Rhodobacter spaeroides. Yeasts: Saccharomyces cerevisiae, Candida utilis. Acitinomycetes: Streptomyces albur, Streptomyces griseus. Fermenting fungi: Aspergillus oryzae, Mucor hiemalis. Effective micro-organisms (EM) find direct application in waste management programs as they have the capability to thrive and reproduce within solid wastes and various residues when provided with suitable conditions. They exhibit the capacity to transform these waste materials into high-quality compost. The EM was used for the conversion of diverse lignocellulosic residues obtained from a large wood industrial complex into a reusable form (Sreenivasan 2013). However, it is important to note that further experimentation is required to firmly establish and recommend the utilization of effective micro-organisms for enhancing the functioning of earthworms.

7.13 Domestic Waste Processing Systems The includes small scale systems of vermicomposting for the disposal of household wastes. They range from simple containers with perforated lids for aeration to more sophisticated commercially produced stacking systems of different sizes and complexity, including circular stacking systems. These are useful for urban waste management particularly if food wastes are not thrown.

7.14 Points to Be Considered When Making Compost In order to make good quality compost in a short time, it is very important to pay special attention to the following: 1. Partial decomposition of raw material (cow dung and crop residues) which takes 15–20 days is very important before adding earthworms in it. 2. You should not feel heat when you put your hand deep in the pile to detect the partial composting of the waste. But if such a situation prevails then the residue is partially composted by alerting the moisture content of the residues.

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3. Maintain 30%–40% moisture content in vermi bed until compost is ready. Earthworms does not work properly when there is more or less moisture in the residues. 4. It is very important to maintain the temperature in pit at 20 to 27 °C. Under bright sunlight, the temperature of the pit rises, causing the earthworms to go to the bottom or remain inactive and eventually die. 5. Never use fresh cowdung in vermibeds because earthworms die in fresh cowdung due to excessive heat. Therefore, fresh cowdung should be cooled for 4–5 days before use. 6. The amount of cowdung in the organic waste used for preparation of compost should be at least 20%. 7. Congress grass before flowering is mixed with cowdung and could be partially used as organic matter to make good compost. 8. If the pH of the residues (around 7.0) is neutral then the earthworms work fast. Therefore, when making compost, the pH of the waste should be kept neutral. For this, while filling the waste in the beds, it is necessary to add ash in it. 9. Do not use any kind of pesticides while making compost. 10. Never use a spade when turning the compost or collecting the finished compost. Due to the use of these devices, there is a possibility of injuring or killing the earthworms. 11. Take out the pieces of glass, nails, stones, plastic, envelopes, etc. from the waste. 12. To protect earthworms from birds, fungi, ants, etc., cover the beds with sacks. 13. Earthworms like darkness very much, so always keep the beds covered with sacks/dry grass, etc. 14. For maximum production of vermicompost, moisture content in the beds should be kept between 30% and 35% and for maximum production of vermicompost, moisture should be kept between 20% and 30%. 15. If the moisture content in vermibeds is more than 35%, then there is a decrease in air circulation, due to which the earthworms come on the upper surface of the bed. 16. For good ventilation, the residues should be turned at least once a week so that the earthworms get a suitable environment for making vermicompost. 17. For maximum production of vermicompost, while leaving earthworms on beds, spray 500 gms of jaggery dissolved in 5–10 L of water on the beds, so that the compost could be prepared faster. 18. 500 gms of Bokashi mixture which consists of wheat husk, gram husk/powder and neem/sarson husk can be dissolved in 5–10 L of water and sprayed on each bed to increase the number of earthworms. 19. For good growth and quality production of earthworms, darkness, moisture, ventilation, partial decomposition of waste, regular care and good management in vermibeds are essential. 20. Cow slurry or Trichoderma powder can be mixed in 50–100  g/bed for rapid decomposition of agricultural residues used in compost. 21. If you want to use processed organic matter other than crop residues and animal residues, then this processed organic matter should be mixed with cowdung in

References

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different proportions so that earthworms should gradually adapt itself to this new medium. 22. If there is a possibility of pest infestation in vegetable residues, then 100 mL of neem based insecticide can be sprayed @ 5–10 kg of material before decomposition of residues. 23. Azotobacter and PSB powder which helps in the decomposition of waste can be sprayed @ 50–100 g/bed so that the compost can be prepared faster. 24. For good compost, the bed temperature should be maintained between 25 and 32 °C. 25. Always choose a high place to make compost. 26. Charcoal powder can be sprayed to protect earthworms from red insects.

References Edwards CA (1988) Breakdown of animal, vegetable and industrial organic wastes by earthworms. In: Edwards CA, Neuhauser EF (eds) Earthworms in waste and environmental management. SPB Academic Publishing, The Hague, pp 21–31 Higa T (1991) Effective microorganisms: a biotechnology for mankind. In: Parr JF, Hornick SB, Whitman CE (eds) Proceedings of first international conference on Kyusei nature farming. USDA, Washington, DC, pp 8–14 Nagavallemma KP, Wani SP, Lacroix S, Padmaja VV, Vineela C, Rao MB, Sahrawat KL (2004). Vermicomposting: recycling wastes into valuable organic fertilizer. Global Theme on Agroecosystems Report no. 8 Nair J, Sekiozoic V, Anda M (2006) Effect of pre-composting on vermicomposting of kitchen waste. Bioresour Technol 97:2091–2095 Parray MA, Wani MG, Rather GM (2014) Stimulatory influence of some additives on vermicomposting by Eudrilus eugeniae. Int J Eng Sci Invent 3(7):1–4 Sreenivasan E (2013) Evaluation of effective micro-organisms technology in industrial wood waste management. Int J Adv Eng Tech IV/III:21–22 Vasanthi K, Chairman K, Michael JS, Kalirajan A, Singh AJAR (2011) Enhancing bioconversion efficiency of the earthworm Eudrilus eugeniae (Kingberg) by fortifying the filter mud vermibed using an organic nutrient on line. J Biol Sci 11(1):18–22

8

Influence of Vermicompost on Soil Health

8.1 Introduction Vermicompost, often referred to as “nature’s wonder fertilizer,” exerts a remarkable influence on soil properties. This nutrient-rich organic material, produced through the digestion and decomposition of organic matter by earthworms, has the capacity to transform soil in numerous beneficial ways. Vermicompost enhances soil structure by promoting the formation of stable aggregates, thereby improving aeration, root penetration, and water infiltration. It acts as a reservoir for moisture, enhancing water-holding capacity of  soil  and reducing the risk of waterlogging or drought stress. Furthermore, vermicompost is a potent source of essential nutrients and micro-organisms that bolster soil fertility, regulate pH levels, and stimulate beneficial microbial activity. Its incorporation into agricultural practices not only enriches the organic matter content of the soil but also supports sustainable farming by reducing the dependence on synthetic fertilizers and promoting healthier, more productive soils. Hence, vermicompost is a natural powerhouse that revitalizes and fortifies soil properties, contributing to the overall health and vitality of the ecosystem.

8.2 Influence of Physiochemical Properties of Soil Vermicompost is known for improving the physiochemical properties of soil. It enhances the various properties of soil such as aggregation of soil, aggregate stability, pH, bulk density, EC, water holding capacity (WHC), organic matter (OM), and nutrient status of the soil. Vermicompost improves the soil structure by improving the soil aggregation and its stability and hence become less vulnerable to calamities such as erosion. The experiment was conducted by Tejada et al. (2009) by applying beet vinasse (BV), vermicompost and compost (prepared by composting vermicompost and beet vinasse) in the soil which is vulnerable to soil erosion. He concluded © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_8

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that BV improved the instability index by 7.9%. On the other hand, vermicompost and the beet vinasse vermicompost reduce the instability index by 11.2% and 13.2%, respectively, in comparison with the soil used as control. The application of vermicompost also results in reducing the large size aggregates in soil and hence results in improving the stability of aggregates in all aggregate size fractions. The reason behind this can be given by that the application of organic matter may result in exchange complex changes that lead to a breakdown of large fractions (Aksakal et al. 2016). The leaching and runoff are reduced at the highest quantity with the application of vermicompost as compared to the control (Doan et  al. 2015). The bulk density of the soil is also reduced with the application of the vermicompost as compared to chemical fertilizers and farmyard manure vermicompost application results in increased concentration of organic matter which in turn reduces the bulk density of soil (Ilker et al. 2016). The pH of the soil is also found to be increased with the application of vermicompost, whereas some of the studies show that the pH of the soil does not change with the application of vermicompost (Gutierrez-Miceli et al. 2007). Contradictorily, vermicompost has also been found to change the pH of soil. These differences are because of the difference in the nutrient content of soil and vermicompost, base content aiding to buffering capacity of soil and capacity to absorb free protons (H+) in the soil (Arancon et al. 2008; Manh and Wang 2014). The vermicompost enhances the electrical conductivity of soil (Gutierrez-Miceli et  al. 2007). It is responsible to reduce the toxicity resulting from saline water and rather increases the growth of plants (Ahmad et al. 2009). Vermicompost also increases the WHC of soil because it possesses high WHC and when applied to soil it improves the porosity of soil making pore spaces available for storing water (Manh and Wang 2014). In comparison to the control soil, vermicompost also results in a higher proportion of hydrophilic/hydrophobic groups of humic substances (Jordao et al. 2002). It has also been reported that the organic carbon per cent of soil is increased with the vermicompost which is otherwise reduced with the application of chemical fertilizers. The reason behind this is chemical fertilizers are devoid of carbon, however, the organic content present in the vermicompost is slowly released into the soil and thus providing the organic carbon to the plants in the available form (Ansari and Kumar 2010; Ansari 2008). Vermicompost improves N, P, and K content of soil to higher levels as compared to other organic and inorganic fertilizers (Karmakar et al. 2013) and further enhances with an increased rate of application (Azarmi et al. 2008a). The micro-nutrients such as copper (Cu), Zinc (Zn), Iron (Fe), and Manganese (Mn) are also increased in the soil with vermicompost application but at suitable concentration (Sangwan et al. 2010; Manivannan et al. 2009). It has been reported that vermicompost can be used for the reclamation of metal contaminated soil. The concentration of heavy metals in such soils is reduced using vermicompost. It has been concluded by Angelova et al. (2013) that available Zn, Cd, Cu, Mn, and Pb content in the soil is reduced by applying vermicompost except for Fe, whereas the compost application results in a further increase in Zn, Cd, Fe, and Mn. The reason behind the increase in heavy metals with the application of compost is the reduction in pH which results in more soluble metal ions. On the other hand, the decrease in heavy metal is due to the organic matter conversion to

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stable form by binding with heavy metals (Angelova et al. 2013). Hence, vermicompost application in the soil contaminated with metal may help in remediation and improvement of soil quality.

8.3 Influence of Vermicompost on Biological Properties of Soil Vermicompost plays an important role in improving the microbial population and its activities where the microbial population is low in the soils amended with chemical amendments (Manivannan et  al. 2009). It has been reported by Tejada et  al. (2009) that the microbial biomass and respiration in the soil are increased by 59.1% and 69%, respectively, with the application of vermicompost in comparison to control soil. Application of vermicompost improves the dehydrogenase, urease, β-glucosidase, phosphatase, and arylsulfatase activities in soil as compared to control. The increased rate of application of vermicompost enhances their enzyme activities at an increased rate (Tejada et al. 2009). Similarly, these enzymes responsible for carbon and phosphorus cycles were found to increase with vermicompost application during celery production in alkaline soil (Ilker et al. 2016).

8.4 Modification in Physico-Chemical Characteristics of Feed Waste Through Vermicomposting The physico-chemical formulation of vermicompost is affected by diverse types of feed material provided to the animal, material used for bedding purposes and with the method the waste is gathered, preserved, and managed before utilization. The elaborations of different changes in physico-chemical parameters of feed material through the process of vermicomposting is as follows:

8.5 pH and Electrical Conductivity (EC) The reason for distinctions in the pH of the vermicompost is the kind of raw material that is utilized for vermicomposting. Various forms of intermediary products are formed as a result of different substrates employed for vermicomposting which indicates diverse behavior in pH shift. For the survival and development of earthworms, the most important condition is pH which should be neutral throughout the vermicomposting. The organic acid bio-conversion or high mineralization of nitrogen into nitrites/nitrates and phosphorus into orthophosphate are attributable by the acidic environment. The pH of cow dung and sheep manure vermicompost came out to be 8.48 and 8.6, (Gutierrez-Miceli et al. 2007) cattle manure had a pH of 6.0–6.7 (Alves et al. 2001; Jordao et al. 2002), pig manure had a pH of 5.3–5.7 (Atiyeh et al. 2001, 2002) and the one obtained from sewage sludge had a pH of 7.2 (Masciandaro et al. 2000). The generation of organic acids and carbon dioxide by microbes in the

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course of bio-conversion of various substrates in the feed provided to earthworms is the reason for the lower pH of the final vermicompost (Chaudhuri et al. 2000; Song et al. 2014). When the number of various types of volatile solids is reduced it results in a reduction in pH and to the growth of earthworms. The greater the rise in growth of biomass, there was large decrease in volatile solids and consequently the more transfer toward the acidic condition (Ndegwa et  al. 2000; Yang et  al. 2014). The drop in pH perhaps is the crucial factor in nitrogen retention because at high pH value this element is lost as volatile ammonia. During the process of decomposition, the production of humic acid and fulvic acid results in reduced pH. The pH changes from acidic to alkaline due to the alteration of the state of mesophilic to thermophilic as a result of the transformation of organic N to NH4 (Fang et al. 1999; Beck-friis et al. 2001), the pH of vermicompost is raised when the surplus of organic nitrogen not needed by microbes was liberated as ammonia which got dissolved in water (Rynk et al. 1994). During vermicomposting of solid waste, tea factory coal ash, beverage bio-sludge, fruits and vegetable waste and home waste respectively, the increase in pH is reported (Datar et al. 1997; Singh et al. 2010; Goswami et al. 2014; Huang et al. 2014; Lleo et al. 2013). The gradual utilization of organic acids and the rise in mineral constituents of the waste is the reason for the rise in pH during the process of composting and vermicomposting. The liberation of CO2, organic acids and combined action microbes and earthworms result in lowering the pH of the vermicompost (Song et al. 2014; Ravindran et al. 2015). The good indicator of appropriateness and assurance of vermicompost is electrical conductivity (EC) (Singh et al. 2016). The information concerning electrical conductivity in the course of the vermicomposting process is contrary, several workers stated reduction in electrical conductivity (Singh et  al. 2016) whereas, others reported rise in electrical conductivity (Song et al. 2014; Yang et al. 2014; Sellami et al. 2008; Hait and Tare 2011). The reason for the decrease in pH could be the decrease in ions after the formation of a complex, on the other hand, the increase in pH could be due to breakdown of organic matter to liberate different types of cations various mineral salts in available forms such as phosphate, ammonium, and potassium (Khwairakpam and Bhargava 2009; Lazcano et al. 2008) or might be due to loss of organic matter (Kaviraj and Sharma 2003).

8.6 Nitrogen Microbial nitrogen transformation such as nitrification, mineralization, and denitrification is affected by earthworms through their interaction with soil biota and increase concentration of ammonia in the fresh vermicasts (Blair et al. 1995). During aerobic composting, nitrogen usually declines because of the utilization of nitrogen by quickly multiplying heterotrophic bacteria but during vermicomposting, the nitrogen level increases (Yang et al. 2014; Singh et al. 2010; Kaur et al. 2010). Chaudhuri et al. (2000) analyzed that during the vermicomposting of kitchen waste by using P. excavates, the potassium and nitrogen content decreases. The reason could be the NH3 volatilization, integration into tissues of earthworm and leaching into bedding

8.7  Organic Carbon and C:N Ratio

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material with as well as without earthworms or due to libration of ammonia (Guest et al. 2001) even though during the vermicomposting process the nitrogen content raised (Manna et  al. 2003; Jadia and Fulekar 2008; Adi and Noor 2009; Nahrul Hayawin et al. 2010; Singh et al. 2010) but in vermicompost, the final TKN content was all the time reliant on the initial nitrogen present in the feed material and the degree of decomposition (Araujo et al. 2004; Garg and Kaushik 2005; Hobson et al. 2005). In nitrogen retention there might also be an important effect of the drop in pH as at higher pH nitrogen is lost as volatile ammonia (Khwairakpam and Bhargava 2009). In the initial feed mixture, there might also exist a good connection between C/N ratio and nitrogen because lower the C/N ratio, the higher will be the rate of decomposition of organic waste and therefore the higher the increase in nitrogen (Parmanik et al. 2007). The C and N mineralization is increased by the burrowing and casting behavior of earthworms as a result of nitrogen-fixing bacteria (Crusmey et al. 2014). The decline in organic carbon might be a crucial factor for the addition of nitrogen. Epidermal glands secrete mucoproteins in the mucus, urea discharged through nephridia and ammonia through the gut with cast materials and also assisted in improving nitrogen content in the vermicompost. In the vermicomposting system, a significant amount of nitrogen is also added by dead worms and their decaying tissues (Needham 1957; Tillinghast 1967; Viel et al. 1987). Most of the level of nitrogen is released from earthworm tissue under decomposition (Whalen et al. 1999). Whalen et al. (1999) found that the excreta of young ones of L. terrestris had more nitrogen content in comparison to the adults at 10 °C but it was reversed in the case of Aporrectodea tuberculate at 18 °C. In soils incubated with earthworms for 48 h, the concentration of NH4-N, NO3-N gets elevated as compared to the soil not incubated with earthworms (Whalen et al. 2000). The dead  earthworms release organic nitrogen up to 21.1–38.6  t/h/year. Kumar et al. (2017) concluded that NH3 volatilization, ammonification, and denitrification resulted in a reduction in nitrogen levels. Benitez et al. (1999), however, reached similar conclusions as they witnessed a loss in total nitrogen by 36% during sewage sludge vermicomposting.

8.7 Organic Carbon and C:N Ratio Compost maturity can be estimated by C:N ratio analysis (Suthar 2010). C:N ratio less than 20 indicates a high degree of organic waste maturation and stabilization, however, C:N ratio less than 15 is preferred agronomic implementation (Padmavathiamma et al. 2008; Sen and Chandra 2007). Song et al. (2014) reported that preferable properties for applying in field exhibited by vermicomposting with C:N ratio less than 12. Mean N2O, P and CO2 fluxes to be higher in samples incubated with earthworms as compared to not incubated with earthworms, but these fluxes were affected by less surviving rate of earthworms that were introduced (Speratti and Whalen 2008). To assess the impact of introduced earthworms on CO2 and NO2 fluxes from temperate agro-ecosystems to a full extent their populations need to be kept in control. Tognetti et al. (2007) had similar observations that vermicompost released a

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greater amount of CO2 in comparison to traditional compost. Early decline in C:N ratio while vermicomposting in comparison to compost without earthworm is noticed by Cabrera et al. (2005). In contrast, Atiyeh et al. (2000) stated gradual decrease in C:N ratio of manure whether with or without earthworms. The reason for reduced organic carbon might be CO2 emissions via strengthened carbon mineralization by earthworm respiration activities and micro-organisms (Deka et al. 2011) which reduce C:N ratio and carbon while vermicomposting. This decrease was reported to an extent from 10% to 45% during the process of vermicomposting of organic waste (Garg and Gupta 2011) while Singh et al. (2013) stated an increase in the content of organic carbon from soil to vermicast. The C:N ratio of vermicompost decreased to 12–17:1 from 21–69:1 (Tripathi and Bhardwaj 2004; Kaviraj and Sharma 2003; Gunadi et  al. 1998; Christy and Ramalingam 2005; Kharrazi et  al. 2014). Saha et  al. (2008) and Parmanik (2010) analyzed that an increase in organic matter oxidation leads to a rapid decrease in organic carbon as a consequence of an increase in increase in earthworm abundance due to a decrease in C:N ratio. Aira and Dominguez (2008) stated carbon losses are high as a result of an increase in microbial biomass in vermicomposting. The mechanism for CO2 regulation was granted by calciferous organs of worms this organ is capable of fixing both environmental and metabolic CO2.

8.8 Phosphorus Phosphorus is an essential nutrient for plant growth and metabolism. It plays a major role in protein formation, metabolism, photosynthesis, seed germination, and flower and fruit establishment. Phosphorus is readily available for plants in the soil in mineral form. Its availability is further enhanced by earthworm activity and phosphate solubilizing micro-organisms (Kharrazi et  al. 2014; Bhat et  al. 2015). The increase in phosphorus levels while vermicomposting, was as a result of mineralization and mobilization of phosphorus, was as an outcome of earthworm’s bacterial and fecal phosphatic activity (Gomez et al. 2015; Parmanik 2010; Lim et al. 2012; Singh et al. 2013; Hanc and Chandimova 2014). Phosphorus gets converted to more available form because of enzyme phosphate during the passage of organic matter through earthworm gut and phosphorus solubilizing organisms may be the reason for the further release. Patron et al. (1999) observed an accelerated transformation of organic phosphorus to more available forms by earthworm activity. E. fetida resulted in 25% and E. eugeniae in 2.4–49.5% increase in phosphorus availability when utilized in vermicomposting of paper waste and sludge rice husk (Bayon and Binet 2006). Ghosh et al. (1999) reported 12–20.9% increase in easily extractable phosphorous by vermicompost. Kaviraj and Sharma (2003) observed that solubilization of insoluble phosphorus and potassium was carried out by acid produced through organic matter decomposition by microbes. This might be a reason for the presence of several gut microbes in earthworms to increase phosphorus content. Effects of Bacillus megaterium (phosphate solubilizing bacteria) and earthworm E. fetida and Pheretima guillelmi on phosphorus rotation a transformation in the

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soil were studied by Mba (1997) and Wan and Wong (2004). Number of B. megaterium was found to increase in all treatments with earthworms. Treatments having earthworm Pheretima guillelmi as well as a gradual rise in both inorganic and water-­ soluble phosphorus showed an increased acid phosphatase activity. This promoted the hydrolysis rate of an organic form of phosphorus into inorganic form and B. megaterium discovered in the worm cast of E. euginae. According to Parmanik (2010), an increase in phosphorus levels may lead to an increase in the adsorption of nitrate anions and phosphate ions replacement from humic colloids. In the final vermicompost, the phosphorus content is found to be 11% higher than the control. The increased number of microflora in the earthworm gut may be responsible for available phosphorus release (Hanc and Chandimova 2014). Edwards and Arancon (2004) recognized that the growth and yield of costly fruit crops can be increased by the application of vermicompost at very low rates and it also improves the soil quality by increasing the microbial biomass and microbial activity. Kang et al. (2011) experimented to analyze the effect of vermicompost on physical and chemical properties, growth and nutrient uptake of muskmelon by applying five treatments of burnt rice hulls (BRH) or coconut husk (CH) in combination with vermicompost at 10%, 20%, 30%, 40%, and 50% (v/v) and concluded that as the proportion of vermicompost mixture increases there was an indicative increase in total porosity, aeration porosity, electrolyte conductivity, pH, bulk density, and macro-nutrients of substrates while water holding capacity, mass wetness and zinc, manganese and copper contents were significantly diminished. They suggested that vermicompost combined with BRH and CH at 20% or 30% gave the best condition for the performance of muskmelon seedlings. The physical, chemical, and biological properties of soil and plant growth are improved by amending of organic matter in soil with either compost or vermicompost. Soil-borne diseases are also suppressed and it helps in inducing systemic resistance against the foliar pathogens. The diversity and population of beneficial microbial communities are amplified through vermicomposting. Some reports indicate that few harmful microbes such as spores of Pythium and Fusarium are dispersed by earthworms but the influence and multiplication of disease-suppressing and plant growthpromoting beneficial bacteria cast out these noxious effects.

8.9 Beneficial Role of Vermicompost in Fruit Crops It had been recorded that the grape yield is boosted by two-fold with the application of vermicompost in comparison to chemical fertilizers. It’s application results in 18% enhancement in bunch numbers and a 23% rise in grape yield in treated vines. Vermicasting application to grapes cultivated on eroded wasteland was found to enrich the quality of both, fruits as well as soil. Grapes fruit crop was grown by a farmer of the Sangli district of Maharashtra, India. He applied vermicast @5 tons/an over eroded wasteland. The results from vermicasts divulged that in the period of 1 year the pH value of soil was decreased from 8.3 to 6.9 and the potash value is elevated from 62.5 to 800 kg/ha. The nutritional quality of grapes

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is also enhanced. An experiment executed to interpret the influence of vermicompost and chemical fertilizers on strawberries (Fragaria bananas). These were applied individually and in combination. Vermicompost was applied @10 tons/ha whereas, the chemical fertilizers (NPK) were applied @85(N):155(P):125(K) kg/ ha. The findings ascertain the upswing in yield and weight of fruits. The economic yield and weight of the largest fruit of strawberry was found to be 35% higher on plants pertained with vermicompost in comparison to inorganic fertilizers in 220  days after transplanting. Furthermore, the rise in the runners by 36% and flowers by 40%, on plants pertained with vermicompost is noticed. The microbial biomass is also considerably stimulated in the soils fed with vermicompost in comparison to chemical fertilizers. It had been demonstrated by various studies that there was an improvement in the yield of strawberries by 32.7% and intense contraction in the incidence of physiological disorders like albinism (16.1% ∆ 4.5%), fruit malformations (11.5% ∆ 4%), gray mould (10.4% ∆ 2.1%) and diseases like botrytis rot. The economic yield quality of strawberries is enhanced by 58.6% by using vermicompost which was found to be credible in ameliorating the nutrient-related disorders. Vermicompost exhibits various desirable impacts on cherries. Its single application improved the yield of cherries for 3 years speculating that vermicompost application enhances and revives the fertility of the soil for a long time. The continual application of vermicompost in the farm reduces its rate to a minimum in the upcoming years. At the first harvest, trees with vermicompost yield an additional yield of $63.92 and $ 70.42 per tree and after three harvests profits per tree were $110.73 and $142.21, respectively. The vermicompost application @10 kg per plant in Citrus reticulata at the time of basin preparation, i.e., during the month of June results in a substantial gain in weight and number of fruits and hence improves yield. An experiment was administered to scrutinize the impact of vermicompost and chemical fertilizers on quality attributes and yield of banana (Musa paradisiaca L.) cv. Grand Naine. The 2-year experiment arrives at the culmination that higher yield of banana can be secured in Kharif seas (under south Saurashtra Agro Climatic condition) either by applying 150-45-100 g NPK per plant or by replacing the inorganic fertilizers with 6 kg vermicompost per plant. Investigations had been commended to study the impact of vermicompost as a substitute organic amendment to inorganic fertilizers on papaya. An experiment was executed to evaluate the influence of vermicompost on the initial growth and yield of papaya. The findings disclosed that the vermicompost shows a favorable effect on the initial growth and yield of papaya when used in the substrate mixture in comparison to the sole application of inorganic fertilizers. Studies regarding the effect of vermiwash on mango (Mangifera indica) indicated that the vermiwash is promising tonic and fertilizer to mango. Application of vermiwash on indigenous and Hapus varieties of mango results in enhanced food production, i.e., from 1.00 (control) to 8.5 (treated) and 1.00 (control) to 3.5 (treated) respectively, enhanced bloosming percentage, improved size, test and luster of fruits. Furthermore, vermiwash drastically reduce the bacterial or fungal diseases without using any pesticide and hence improve the quality and yield of mango.

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8.10 Beneficial Role of Vermicompost in Vegetable Crops Research has indicated the positive impact of vermicompost and earthworms on the growth and quality of key vegetable crops like tomato (Lycopersicum esculentus), okra (Abelmoschus esculentus), and eggplant (Solanum melongena). These studies have demonstrated notable improvements in both field performance and produce quality (Azarmi et al. 2008b; Ansari and Kumar 2010). Another study focused on the growth effects of earthworms, vermicompost, cow dung compost, and chemical fertilizers specifically on okra cultivation. The application of vermicompost and earthworms has been shown to enhance the growth of vegetable crops, leading to increased flower production and improved fruit development. Remarkably, plants treated with vermicompost and earthworms exhibited significantly lower incidences of diseases such as Yellow Vein Mosaic, Color Rot, and Powdery Mildew (Ansari and Kumar 2010). In India, research conducted on potato production using vermicompost in reclaimed soil has revealed a substantial increase in overall potato productivity when vermicompost was applied at a rate of 6  tons per hectare, in comparison to a control group that yield 4.36 tons per hectare. The application of vermicompost has been found to enhance soil quality by increasing nitrogen content and reducing soil toxicity. An examination focused on garden pea (Pisum sativum) compared the effects of organic manure, which included earthworm vermicast, with those of inorganic fertilizers. The results demonstrated that vermicast led to the growth of taller green pod plants, higher protein and carbohydrate percentages, increased green grain weight per plant, and improved green pod yields (with improvements ranging from 24.8% to 91%) when compared to the use of inorganic fertilizers (Nielson 1965). Similarly, experiments conducted to assess the influence of vermicompost and chemical fertilizers on hyacinth beans (Lablab purpureus) revealed that various growth and yield parameters, including fruit length, fruit production per plant, total chlorophyll content in leaves, dry matter production, flower development, dry weight of 100 seeds, plot yield, and hectare yield, exhibited relative improvements in plots treated with vermicompost, either alone or in combination with inorganic fertilizers. The highest fruit yield of 109 tons/ha was recorded in plots that receive vermicompost @2.5 tons/ha (Gupta et al. 2007). With a rise in plant growth and productivity, the nutritional quality may also be enhanced with the application of vermicompost in some vegetable crops such as tomato, Chinese cabbage (Wang et al. 2010), spinach (Peyvast et al. 2008), strawberries (Singh et al. 2008), and lettuce. Investigations for analyzing the effect of vermicompost on red seedless watermelon suggest that when vermicompost is applied @15  tons/ha results in raised stomatal conductance, transpiration rate and 50% flowering takes place in limited days as compared to control and with other treatments of vermicompost at different rates. Furthermore, when the rate of vermicompost is increased to 20  tons/ha it firmly influences the leaf area, weight of fruits, number of flowers, net photosynthetic area, and internal carbon dioxide. Moreover, the quality traits of watermelon such as TSS, pH, Juice and ash content, rind thickness is also enriched with vermicompost application @15–20 tons/ha. The overall productivity of vegetables such

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as potato (Solanum tuberosum), spinach (spinacia oleracea), and turnip (Brassica campestris) was found to be bolstered with vermicompost application @6 tons/ha. Studies suggest that when vermiwash and vermicompost are used in combination results in increased shoot length of tomato. Various research studies on the influence of vermicompost on vegetable crops demonstrated that the vermicompost improves seed germination in okra, chili, brinjal, and tomato. Germination of groundnut was found to be 100% when sowing of seeds was accomplished in 10 kg soil comprising 200  gm of vermicompost. It also enhances the root and shoot length in brinjal, tomato, okra, and chili. Vermicompost enhances plant growth by releasing plant growth regulators. The researchers administered the studies to elaborate on the impact of compost/vermicompost prepared from the water hyacinth and neem on plant growth (Gajalakshmi and Abbasi 2004a, b; Gajalakshmi 2002). In the first experiment, the study revealed that there is no harmful effect of vermicompost/ compost prepared from water hyacinth on lady’s finger (Abelmoschus esculentus), cluster bean (Cyamopsis tetragonoloba), brinjal (Solanum melongena), tomato (Lycopersicon esculentum), and chili (Capsicum annum). The growth of vegetables treated with vermicompost is improved as compared to the normal growth of vegetables without such treatment. In another experiment, the vermicompost is prepared by using neem (Azadirachta indica), applied to the brinjal plant indicated the increase in plant height, length of roots, more biomass per unit time, early flowering, and improved yield of fruit.

8.11 Nutrient Recovery from Kitchen Bio-Waste The moisture content of the kitchen waste generated from homes and restaurants is more. Hence vermicomposting of kitchen waste is not easier without the addition of any bulking agent. The pre composting of kitchen biowaste must be practiced for 2 weeks to reduce its temperature below 25 °C (Frederickson et al. 1997; Ndegwa and Thompson 2001; Tognetti et al. 2005). Before the vermicomposting, the pre-­ composted material should essentially be allowed to cool down and let the earthworms crawl their themselves. Hanc and Pliva (2013) revealed in their study that the kitchen bio-waste left for pre-composting represents increased total content of N as compared to the feedstock. They recommended for the addition of paper in the kitchen bio-waste for vermicomposting because of its high water absorption capacity, and biodegradable and non-toxic nature (Gupta and Garg 2009). Moreover, it is a favorable feed for earthworms as it enables them to produce cellulose enzymes for it decommissions (Ueda et al. 2010). Inclusion of paper results in decreased initial total N but in the ultimate product vermiculite concentration ratio is enhanced. At the end of the vermicomposting process, the increased total content of macro-­ elements (K, Mg, Ca, P) is noticed. The concentrations of Ca and Mg is increased to higher levels. Another investigation disclosed that, to eliminate the pathogens from the kitchen-­ waste pre-composting of the waste is essential for 9 days and further the vermicomposting for 2.5  months. The elimination of pathogens is only possible if the

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temperature during pre-composting reaches higher enough, otherwise, there are possibilities of not only the activation of pathogens but also their proliferation (Nair et al. 2006).

8.12 Integration of Composting and Vermicomposting Literature represents the powerful ritualistic association among earthworms and micro-organisms, that could prove to be profitable concerning adequate degradation of organic waste (Singh et al. 2011). Micro-organisms resides in the intestine and gut of the earthworms. These microbes are nurtured from organic waste material and convert it into particles of finer size after decomposition. Consequently, the earthworms are nourished by micro-organisms and in exchange, the microbial activity is enhanced by earthworms with the production of casts and fecal material which are microbially active (Edwards 1988). In the process of composting, micro-­ organisms undergo decomposition of organic waste in aerobic condition, however, the process of vermicomposting include both earthworms as well as micro-­organism (Singh et al. 2011). Despite the facts, the vermicomposting process is regarded as superior as compared to the composting in respect of the proficiency to assassinate pathogens (Neklyudov et al. 2008; Dominguez et al. 1997). Whereas, according to some investigations, the process of vermicomposting is not capable to kill pathogens which is a crucial shortcoming as compared to the thermophilic composting (Ndegwa and Thompson 2001). The reason behind its incapability to destroy pathogens is the temperature range which is regarded up to 35 °C (Edwards 1988), which is not sufficient to eliminate the pathogens and if the temperature surpasses this range, it enhances the mortality rate of earthworms. On the other hand, in thermophilic composting, the maximum temperature attained is 70 °C, which is effective in eradicating a diverse range of pathogens.

8.13 Importance of Vermicompost Numerous such components are recognized to be present in the vermicasts which are credible to boost the soil with their application (Ismail 1997; Lee 1985; Abbott and Parker 1981). It improves the water holding capacity of the soil and make nutrients available to the plants in a superior manner (Ismail 1998; Curry and Byrne 1992). Earthworms used in vermicomposting are known to increasingly modify the phosphorus forms, hence proves the vermicomposting as a fruitful technology for furnishing superior phosphorus nutrition from distinct organic waste (Reinecke et al. 1992; Ghosh et al. 1999). The investigations revealed that the earthworm castings contained increased about, i.e., two to three-time additional available potassium as compared to the surrounding soil. Castings of earthworms are also a rich source of ammonium and comprise sites of increased identification potential (Elliott et al. 1990). Furthermore, these castings are embellished with N and have decreased pH and C/N ratio as compared to the surrounding soil and normal compost without

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any regards with the organic waste source (Parkin and Berry 1994). The population of micro-organisms is likewise elevated in vermicompost as compared to the compost (Chowdappa et al. 1999). The castings of red worms are rich in humus that assist the formation of clusters of soil particles which formulate channels that helps in easy movement of air and improves water holding capacity of the soil. Worms also enhance the penetration of water into the soil by 50% (Ghabbour 1973; Capowiez et al. 2009). The nutrients are contained in the earthworm hastings and are generated slowly to the plants in the available form. The plant nutrients present in the castings of earthworms are enveloped in mucus membranes that are liberated by the earthworms. Vermicompost is rich in actinomycetes and antibiotics that improve the biological resistance in crop plants against disease and pest attack and therefore, reduce the use of inorganic pesticides up to 75% (Suhane 2007). Several studies revealed that the concentration of enzymes and hormones in the vermicast produces dual function, i.e., encourage the growth of plants and depress pathogens population (Ismail 1997). The applied vermicompost impede the infection of Fusarium oxysporium f. sp. Lycopersici in tomato plants and the defensive impact is enhanced in ratio to the application rate of vermicompost. Research shows that biogenic CO2 is generated in huge amounts through both composting as well as vermicomposting on large as well as small scale units. Though, the liberation of N2O with vermicomposting attributed to potently notifying conditions in the vermibeds along with the de-nitrifying bacteria inside the gut but CH4 is liberated in traces only (Hobson et al. 2005). It had been suggested that the process of vermicomposting is further fruitful in stabilizing the organic waste as it results in nutrient-­ rich vermicompost and liberate reduced amounts of CH4 compared to the composting (Swati and Hait 2018). The vermicomposting process is responsible in reducing the C:N ratio and enhance the N concentrations as compared to the traditional methods of composting of the household waste with its conversion into compost in 30 days (Gandhi 1997). It also plays an important role in the nitrogen cycle, particularly in recycling N under shifting cultivation. The participation of earthworms in N cycle under shifting cultivation is during the fallow period between two crops on the same piece of land in 5–15 years. They play their role in N cycling through mucus production, decomposition of dead tissues, and cast-egestion. The earthworms in the vermicompost are accountable for the preparation of the ground in a superior way to permit the proper growth of the plants with fibrous roots and seedlings of all types. It is disclosed through various investigations that earthworms yield specific vitamins, metabolites, and identical materials into the soil which are advantageous for the growth of plants (Nielson 1965).

8.14 Environmental Applications of Vermicompost Vermicompost is employed for the treatment of aqueous media as it was revealed by the numerous studies that vermicompost acts as an absorbent organic pollutants and metals that are toxic included in the aqueous media. The soils which are polluted

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can be restored with the application of vermicompost and it also results in decreased mobility of hazardous chemicals. Studies revealed that the application of vermicompost was proved victorious in abating the concentrations of a herbicide [3-(3,4-dichlorophenyl)-1,1-dimethylurea, or diuron] in the soils (Fernandez-Bayo et al. 2008). However, the sufficient polarity in the diuron results in the substantial affection between this compound and the hydrophilic group of vermicompost, with the resultant dissemination of this herbicide through distinct horizons of amended soils. Furthermore, the application of vermicompost was proved incapable of removal of polycyclic hydrocarbons (PAHs) from the soil (Alvarez-Bernal et  al. 2006). The investigations confirmed that the vermicompost is not only the source of micro-organisms but it also supplies the nutrients to native microbiota of the ecosystem. This viewpoint elaborates that the population application of vermicompost rebuilt the population of micro-organisms in the soil polluted with the herbicides (Delgado-Moreno and Pena 2009; Fernandez-Bayo et al. 2009). Vermicompost is also capable of bio-remediation of metallic species contained in the soil (Jordao et al. 2002). Various studies suggested that the application of vermicompost in the soils enhance the agricultural productivity. Its application enhances the germination rate of seeds because of increase in soil temperature, retention of water which is enhanced by a huge number of hydrophilic groups in the vermicompost structure, nutrients required for the plant growth namely nitrogen, exchangeable calcium, phosphorus, soluble potassium and magnesium, and soil aggregation (Kavamura and Esposito 2010). Vermicompost plays an important role in the bio-control of agricultural diseases. Because with its application in the soil huge amounts of nutrients are liberated for the plants which results in an ultimate increase in the natural defense system of the plants against diseases (Singh et al. 2008; Sahni et al. 2008; Adhikary 2012).

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Patron JC, Sanchez P, Brown GG, Brossard M, Barois I, Gutierrez C (1999) Phosphorus in soil and Brachiaria decumbens plants as affected by the geophagous earthworm Pontoscolex corethrurus and phosphorus fertilization. Pedobiologia 43:547–556 Peyvast G, Olfati JA, Madeni S, Forghani A (2008) Effect of vermicompost on the growth and yield of spinach (Spinaciaoleracea L.). J Food Agric Environ 6:110–113 Ravindran B, Contreras-Ramos SM, Sekaran G (2015) Changes in earthworm gut associated enzymes and microbial diversity on the treatment of fermented tannery waste using epigeic earthworm Eudrilus eugeniae. Ecol Eng 74:394–401 Reinecke AJ, Viljoen SA, Saayman RJ (1992) The suitability of Eudrilus eugeniae, Perionyx excavatus and Eisenia foetida (Oligochaeta) for vermicomposting in southern Africa in terms of their temperature requirements. Soil Biol Biochem 24:1295–1307 Rynk RM, Kamp VD, Willson GG, Singley ME, Richard TL, Kolega JJ, Gouin FR, Laliberty L Jr, Kay D, Murphy DH, Hoitink AJ, Brinton WF (1994) On-farm composting handbook. Northeast Regional Agricultural Engineering Service, Cooperative Extension, New York Saha S, Pradhan K, Sharma S, Alappat BJ (2008) Compost production from municipal solid waste (MSW) employing bioinoculants. Int J Environ Waste Manag 2:572–583 Sahni S, Sarma BK, Singh DP, Singh HB, Singh KP (2008) Vermicompost enhances performance of plant growth-promoting rhizobacteria in Cicer arietinum rhizosphere against Sclerotium rolfsii. Crop Prot 27:369–376 Sangwan P, Kaushik CP, Garg VK (2010) Vermicomposting of sugar industry waste (pressmud) mixed with cow dung employing an epigeic earthworm Eisenia foetida. Waste Manag Res 28:71–75 Sellami FR, Jarboui S, Hachicha K, Medhioub EA (2008) Co-composting of oil exhausted olive-cake, poultry manure and industrial residues of agro-food activity for soil amendment. Bioresour Technol 99:1177–1188 Sen B, Chandra TS (2007) Chemolytic and solid state spectroscopic evaluation of organic matter transformation during vermicomposting of sugar industry waste. Bioresour Technol 98:1680–1689 Singh R, Sharma RR, Kumar S, Gupta RK, Patil RT (2008) Vermicompost substitution influences growth, physiological disorders, fruit yield and quality of strawberry (Fragaria x ananassa Duch.). Bioresour Technol 99:8507–8511 Singh J, Kaur A, Vig AP, Rup PJ (2010) Role of Eisenia foetida in rapid recycling of nutrients from bio sludge of beverage industry. Ecotoxicol Environ Saf 73:430–435 Singh RP, Embrandiri A, Ibrahim MH, Esa N (2011) Management of biomass residues generated from palm oil mill: vermicomposting a sustainable option. Resour Conserv Recycl 55:423–434 Singh A, Jain A, Sarma BK, Abhilash PC, Singh HB (2013) Solid waste management of temple floral offerings by vermicomposting using Eisenia foetida. Waste Manag 33:1113–1118 Singh SP, Singh J, Vig AP (2016) Earthworm as ecological engineers to change the physico-­ chemical properties of soil: soil vs vermicast. Ecol Eng 90:1–5 Song X, Liu M, Wu D, Qi L, Ye C, Jiao J, Hu F (2014) Heavy metal and nutrient changes during vermicomposting animal manure spiked with mushroom residues. Waste Manag 34:1977–1983. https://doi.org/10.1016/j.wasman.2014.07.013 Speratti AB, Whalen JK (2008) Carbon dioxide and nitrous oxide fluxes from soil as influenced by anecic and endogeic earthworms. Appl Soil Ecol 38:27–33 Suhane RK (2007) Vermicompost. Rajendra Agriculture University, Pusa Suthar S (2010) Recycling of agro-industrial sludge through vermitechnology. Ecol Eng 36:1028–1036 Swati A, Hait S (2018) Greenhouse gas emission during composting and vermicomposting of organic wastes—a review. Clean Soil Air Water 46:1700042 Tejada M, Garcia-Martinez AM, Parrado J (2009) Effects of a vermicompost composted with beet vinasse on soil properties, soil losses and soil restoration. Catena 77:238–247 Tillinghast EK (1967) Excretory pathways of ammonia and urea in the earthworm Lumbricus terrestris. J Exp Zool 166:295–300

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Tognetti C, Laos F, Mazzarino MJ, Hernandez MT (2005) Composting vs. vermicomposting: a comparison of end product quality. Compost Sci Util 13:6–13 Tognetti C, Mazzarino MJ, Laos F (2007) Cocomposting biosolids and municipal organic waste: effects of process management on stabilization and quality. Biol Fertil Soils 43:387–397 Tripathi G, Bhardwaj P (2004) Comparative studies on biomass production, life cycles and composting efficiency of Eisenia foetida (Savigny) and Lampito mauritii (Kinberg). Bioresour Technol 92:275–278 Ueda M, Goto T, Nakazawa M, Miyatake K, Sakaguchi M, Inouye K (2010) A novel cold-adapted cellulase complex from Eisenia foetida: characterization of a multienzyme complex with carboxymethylcellulase, β-glucosidase, β-1, 3 glucanase, and β-xylosidase. Comp Biochem Physiol B Biochem Mol Biol 157:26–32 Viel M, Sayag D, Andre L (1987) Optimization of agricultural, industrial waste management through in-vessel composting. In: de Bertoldi M (ed) Compost: production, quality and use. Elseiver Applied Science, Essex, pp 230–237 Wan JHC, Wong MH (2004) Effects of earthworm activity and P-solublising bacteria on P availability in soil. J Plant Nutr Soil Sci 167:209–213 Wang D, Shi Q, Wang X, Wei M, Hu J, Liu J, Yang F (2010) Influence of cow manure vermicompost on the growth, metabolite contents, and antioxidant activities of Chinese cabbage (Brassica campestris ssp. chinensis). Biol Fertil Soils 46:689–696 Whalen JK, Paustian KH, Parmelee RW (1999) Simulation of growth and flux of carbon and nitrogen through earthworm. Pedobiologia 43:37–546 Whalen JK, Parmelee RW, Subler S (2000) Quantification of nitrogen excretion rates for three lumbricid earthworms using 15N. Biol Fertil Soils 32:347–352 Yang J, Lv B, Zhang J, Xing M (2014) Insight into the roles of earthworm in vermicomposting of sewage sludge by determining the water-extracts through chemical and spectroscopic methods. Bioresour Technol 154:94–100

9

Harvesting of Vermicompost

9.1 Introduction Earthworms have inhabited the Earth for more than two decades. Throughout this extensive period, they have dutifully fulfilled their role in sustaining the perpetual cycle of life. Although their task is straightforward, it holds immense significance. Earthworms serve as nature’s agents for recycling organic nutrients, effectively converting them from deceased tissues back into nourishment for living organisms. Vermicomposting is a composting method that employs specific earthworm species to expedite the organic waste conversion process, resulting in a superior final product. Vermicompost is considered mature and ready for harvest when nearly all of the raw materials, except for a few, typically woody stems, have undergone complete decomposition. At this stage, the vermicomposting ingredients have undergone both thermophilic and mesophilic decomposition processes. The height of the compost pile will have reduced to approximately one-third to one-half of its original size, and the pile temperature will have reached near-ambient levels. The organic substrates are no longer distinguishable, and the vermicompost exhibits a darkish brown, crumbly texture with an earthy scent, resembling that of freshly excavated fertile soil. A finished compost suitable for use as a soil amendment will not emit a strong offensive odor.

9.2 Vermicompost Vermicomposting is the process of transforming organic matter into valuable worm castings, which play a pivotal role in enhancing soil fertility. These castings are rich in essential nutrients such as nitrogen, potassium, phosphorus, calcium, and magnesium. In fact, they contain significantly higher levels of nutrients compared to quality top soil, with approximately 5 times more available nitrogen, 7 times more available potash, and 1½ times more calcium. Earthworm castings are renowned for © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_9

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their contributions to soil quality, as they improve aeration, porosity, structural integrity, drainage, and moisture retention. Additionally, the castings, coupled with the natural soil cultivation by earthworms through their burrowing activity, enhance water permeability in the soil. Remarkably, worm castings have the capacity to retain nearly nine times their weight in water. The process of “vermiconversion,” which utilizes earthworms to convert waste materials into valuable soil additives, has been practiced on a relatively small scale for some time. The recommended rate for applying vermicompost is typically within the range of 15–20%.

9.2.1 Materials for Preparation of Vermicompost Any types of biodegradable wastes such as: • • • • • • •

Crop residues Weed biomass Vegetable waste Leaf litter Hotel refuse Waste from agro-industries Biodegradable portion of urban and rural wastes.

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9.2.1.1 Phases of Vermicomposting Phase 1: This phase encompasses waste collection, shredding, mechanical separation of metals, glass, and ceramics, as well as the storage of organic waste. Phase 2: In this phase, the organic waste is subjected to a pre-digestion period of 20 days. The material is stacked alongside cattle dung slurry. This process initiates partial digestion of the material, making it suitable for earthworm ­consumption. It is important to note that cattle dung and biogas slurry can be used after drying, and wet dung should not be employed in vermicompost production. Phase 3: This stage involves the creation of an earthworm bed, necessitating a concrete base where the waste is placed for vermicompost preparation. A firm base is essential to prevent the worms from burrowing into the ground and to ensure that all soluble nutrients are retained within the compost during watering. Phase 4: During this phase, earthworms are gathered after the vermicompost collection. The composted material is then shifted to separate fully composted material. The partially composted material is returned to the vermicompost bed for further processing. Phase 5: The vermicompost is stored in an appropriate location to retain moisture and foster the growth of beneficial micro-organisms.

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9.2.2 The Five Essentials Compost worms need five basic things: • • • • •

A suitable habitat, often referred to as ‘bedding’ A source of nourishment Sufficient moisture (typically exceeding 50% water content by weight) Proper aeration Safeguarding against temperature extremes.

9.2.3 Harvesting Vermicompost In the tub method of composting, castings formed on the upper layer are periodically collected, typically once a week. Castings are manually scooped out and placed in a shaded area, forming a heap-like structure. The harvesting of castings should be limited to the layer where earthworms are present. This periodic harvesting is essential to ensure unobstructed compost quality and prevent compaction when watering. In the small bed vermicomposting method, there is no need for regular harvesting. Since the waste material is piled to a height of about 1 foot, the resulting vermicompost is harvested once the process is complete. The process of gathering the compost involves retrieving fully developed castings from the beds. These castings, appearing black or dark brown, are the crumbly worm compost, the desired end product. To maintain the health of the worms, it is essential to harvest the compost and introduce fresh bedding bi-annually. The compost can be gathered by laying a plastic sheet under ample light or sunlight. The bed contents, excluding the bedding materials, are arranged in several mounds on the sheet. The worms, seeking shelter from the light, will move toward the center of each mound, allowing easy collection of the worm compost from the outer edges. The crawling worms can be gathered for subsequent use.

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9.2.4 Harvesting Earthworm After the completion of production of vermicompost, earthworms can be collected from the tub or small bed using a trapping method. This involves creating fresh cow dung balls, typically positioned at five or six locations within the vermibed before the compost is harvested. After 24 h, the cow dung balls are retrieved, with numerous worms attached. Submerging this dung ball in a bucket of water will separate the worms. These collected worms are subsequently employed for the next composting cycle. Worm harvesting is often carried out with the purpose of selling the worms, rather than for establishing new worm beds. If the aim is to expand the operation, such as creating new beds, it can be achieved by dividing the existing beds. This process involves taking a section of the bed to initiate a new one and replenishing the original bed with fresh bedding and feed materials. However, when worms are being prepared for sale, they are usually separated, weighed, and transported in a relatively sterile medium, such as peat moss. To achieve this, the worms must be separated from the bedding and vermicompost. Growers utilize three main methods for worm harvesting: manual, migration, and mechanical. The details of each of these techniques are provided in the subsequent sections.

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9.2.4.1 Manual Methods Manual methods are commonly employed by hobbyists and smaller-scale growers, especially those who provide worms to the home-vermicomposting or bait markets. In essence, manual harvesting involves the process of hand-sorting or manually picking the worms directly from the compost. This process can be made more efficient by taking advantage of the worms’ aversion to light. When material containing worms is stacked on a flat surface with a light source placed above, the worms will promptly retreat beneath the surface. The harvester can then remove a layer of compost, stopping when worms become visible again. This cycle is repeated multiple times until what remains on the table is primarily a cluster of worms gathered beneath a thin layer of compost. These worms can then be promptly collected into a container, weighed, and prepared for transportation. There may be minor variations and potential enhancements to this method. For instance, some may opt to use a container instead of a flat surface or create multiple piles simultaneously. This way, the harvester can transition from one pile to another, circling back to the initial one when it’s time to remove the next compost layer. Nevertheless, all of these techniques require a significant amount of manual labor and are primarily practical when dealing with a small-scale operation where the worms hold substantial value. 9.2.4.2 Self-Harvesting (Migration) Methods These approaches, akin to certain techniques employed in vermicomposting, capitalize on the natural inclination of worms to migrate toward new areas, either in search of fresh sustenance or to escape unfavorable circumstances like aridity or light. However, in contrast to the manual techniques described earlier, these methods employ simpler tools like screens or onion bags. The screen method is a commonly used and uncomplicated approach. It entails creating a box with a mesh bottom, typically using a ¼-inch mesh, although a 1/8-­ inch mesh can also be employed. There are two distinct variations of this method. The downward-migration system resembles the manual method, as it relies on bright light to encourage the worms to move downward. However, in the screen system, the worms pass through the mesh into a prepared container filled with pre-­ weighed moist peat moss. Once all the worms have made their way through, the compost in the box is removed, and a fresh batch of compost filled with worms is introduced. This process is repeated until the peat moss-filled box reaches the desired weight. Similar to the manual approach, this system can be set up in multiple locations simultaneously, allowing the worm harvester to move efficiently from one box to another without waiting for the worms to migrate. The upward migration system operates on a similar principle, with the exception that a container with a mesh bottom is positioned directly atop the worm bed. This container is filled with a few centimeters of damp peat moss and then sprinkled with an enticing worm attractant, such as coffee grounds, chicken mash, or fresh cattle manure. Once it is evident through visual inspection that a sufficient number of worms have moved into the material, the container is removed and weighed. This method is notably used in Cuba, where large onion bags are substituted for boxes. While this technique minimizes disturbance to the worm beds but still there is a

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downside that the harvested worms are still enclosed within material that contains some unprocessed food, potentially causing messiness and the risk of overheating during transportation. To address this heating concern, one can eliminate any visible food residues and allow some time for the worms to consume any remaining traces before packaging. The most efficient and convenient way to separate worms from vermicompost involves the use of mechanical harvesters. According to Bogdanov (1996), a mechanical harvester is essentially a trommel device, a cylindrical structure measuring approximately 8–10 feet in length and 2–3 feet in diameter. The walls of this cylinder are constructed using various screen materials with different mesh sizes. A small electric motor is affixed to one end of the cylinder to enable its rotation. The trommel is set at an incline, and at the upper end of the rotating cylinder, worms, along with their bedding and castings, are introduced. As the cylinder turns, the castings fall through the screen, while the worms traverse the entire length of the trommel and exit through the lower end, ready to be collected in a wheelbarrow.

9.2.5 Storing and Packing of Vermicompost The vermicompost that has been harvested should be stored with great care in a cool, dark environment, ensuring that it retains a minimum moisture content of 40%. Protection from direct sunlight is crucial to prevent moisture and nutrient loss. It is advisable to initially store the composted material openly rather than immediately packing it into sacks. Packing can be postponed until it is ready for sale. If

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open storage is chosen, occasional watering may be necessary to maintain the proper moisture level and support the beneficial microbial community. In cases where storage is necessary, the use of laminated sacks is recommended to minimize moisture evaporation. Vermicompost can be safely stored for up to 1 year without any deterioration in quality, as long as the moisture level is maintained at approximately 40%.

9.2.6 Precautions During the Process Followings are some vermicomposting:

recommended

precautions

to

be

taken

during

• Ideal earthworm species for vermicomposting are the African species, Eisenia fetida, and Eudrilus eugeniae, while many Indian species are not suitable for this purpose. • Use only plant-based materials like grass, leaves, or vegetable peelings when preparing vermicompost. • Avoid materials of animal origin such as eggshells, meat, bones, chicken droppings, etc., as they are not suitable for vermicomposting. • Certain items like Gliricidia loppings, tobacco leaves, onions, garlic, and chilli from kitchen waste are also not suitable for earthworm rearing. • Protect earthworms from potential threats such as birds, termites, ants, and rats. • Maintain adequate moisture throughout the vermicomposting process. Both stagnant water and a lack of moisture can be harmful to earthworms. • Periodically remove the vermicompost from the bed and replace it with fresh waste materials once the process is complete. Hence, the vermicompost is typically ready for harvest within a period of 60–90 days. During this time, the material undergoes a transformation, turning into a granular, black, lightweight, crumbly, moderately loose, and humus-rich substance. To facilitate the separation of worms from the compost, it is advisable to refrain from watering the beds for a period of 2–3 days before emptying them. One effective method for harvesting vermicompost involves creating a pyramidal heap. This approach leverages the earthworm’s natural sensitivity to light, prompting them to move deeper into the pyramid. The vermicompost can then be collected from various parts of the heap, including the bottom, sides, and top surface, either by hand or with the use of a trowel.

Reference Bogdanov P (1996) Commercial vermiculture: how to build a thriving business in redworms. VermiCo Press, Oregon

By-Product and Value-Added Products

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10.1 Vermiwash During the vermicomposting process, the bed is filled with organic waste, bedding materials, and earthworms. This setup includes a drainage and collection system to manage the moisture content introduced through the activity of the worms. Vermicomposting naturally generates a leachate as a result of this moisture addition, and it is crucial to drain this leachate to prevent over-saturation of the vermicomposting unit and the attraction of pests. This collected leachate is known as vermiwash. Vermiwash has significant benefits, as it can serve as a liquid fertilizer due to its high concentration of plant nutrients. It comprises excretory products and mucous secretions from the earthworms, along with micro-nutrients derived from organic molecules. A portion of this liquid comes from the earthworms’ bodies, as they contain ample water content. Vermiwash is particularly rich in amino acids, vitamins, and essential nutrients such as nitrogen, potassium, magnesium, zinc, calcium, iron, and copper. Additionally, it contains certain growth hormones like auxins and cytokinins. Vermiwash is also rich in nitrogen-fixing and phosphate-solubilizing bacteria, including species like nitrosomonas, nitrobacter, and actinomycetes. When collected correctly, vermiwash appears as a clear, transparent, honey-brown fluid. However, it is essential to conduct a plant bioassay test on vermiwash before using it as a foliar spray. This test helps determine the presence of any pathogens or phytotoxic compounds that could potentially harm plants. If vermiwash is employed as a fertilizer, it is advisable to dilute it to prevent any damage to plants. However, dilution also reduces its nutrient concentration, so it may need to be combined with other mineral fertilizers for optimal results. In some cases, commercial liquid fertilizer formulations may include specific chemical compounds, such as polyoxyethylene tridecyl alcohol as a dispersant and polyethylene nonylphenol as an adherent. These compounds are added to enhance nutrient availability to plants. Vermiwash possesses significant properties for promoting plant growth (Suthar 2010) and effectively controlling pests. A study conducted by © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_10

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Giraddi (2003) revealed that weekly applications of vermiwash led to a 7.3% increase in radish yield. Another study, conducted by Thangavel et al. (2003), also reported enhanced growth and yield in paddy crops with the application of vermiwash and vermicast extracts. Ansari and Sukhraj (2010) documented the impact of vermiwash and vermicompost on soil characteristics and the productivity of okra (Abelmoschus esculentus). Additionally, a recent study by Rekha et al. (2013) investigated how vermicompost and vermiwash influenced the growth and productivity of black gram (Vigna mungo). Farmers in North India’s Bihar region have reported growth-promoting and pesticidal qualities of this liquid product. They have successfully applied it to crops such as brinjal and tomato, resulting in robust plants that yield larger, exceptionally shiny fruits. The utilization of vermiwash through spray applications has proven highly effective in controlling pest infestations and diseases, significantly reducing the need for chemical pesticides and insecticides on vegetable crops. This, in turn, has enhanced the market value of the produce. To assess its effectiveness against thrips and mites in managing these pests on chilli plants, vermiwash was employed in three different dilutions (1:1, 1:2, and 1:4) when mixed with water for both “seedling dip” treatment and “foliar spray” applications (Saumaya et al. 2007). Giraddi (2003) also observed a significantly lower pest population in chilli plants treated with vermiwash. This treatment involved soil drenching 30 days after transplanting and foliar spraying at 60 and 75 days after transplanting, in comparison to untreated crops. Additionally, Suthar (2010) identified hormone-like substances in vermiwash and conducted a study to assess its impact on seed germination, root development, and shoot length in Cyamopsis tetragonoloba. The results were compared with those of a urea solution (0.05%). It was found that the highest germination rate, reaching 90%, occurred with 50% vermiwash, while the urea solution achieved a germination rate of 61.7%. Furthermore, the maximum root and shoot lengths were recorded at 8.65 and 12.42 cm, respectively, with 100% vermiwash, whereas urea resulted in lengths of 5.87 and 7.73 cm.

10.1.1 Steps for Preparation Following steps are involved for preparing vermiwash: 1. Choose a plastic container with a capacity of approximately 50 L. 2. Create a hole at the bottom and attach a tap using a safety gauge. 3. Place a layer of broken bricks or stone pieces with a thickness of 10–15 cm in the container. 4. Add another layer of sand with a thickness of 10–15 cm on top of the bricks. 5. Follow this with a layer of partially decomposed cow dung, approximately 30–45 cm thick. 6. Add another layer of soil with a thickness of 2–3 cm. 7. Introduce 100–200 earthworms into the container. 8. Place a layer of paddy straw, approximately 6 cm thick.

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9. Regularly spray water over the layers for a period of 7–8 days. 10. After 10 days, the liquid vermiwash will be produced. 11. Hang a pot with a bottom hole over the container so that water drips slowly. 12. Each day, pour 4–5 L of water into the hanging pot. 13. Position another pot under the tap to collect the vermiwash.

10.2 Vermicompost Tea Vermicompost tea, also known as Liquid Vermicompost, is a type of compost tea produced by steeping vermicompost in water. It contains beneficial micro-­organisms that can potentially help to reduce or manage diseases and enhance soil quality. Research suggests that this tea may have a positive impact on controlling plant-­ parasitic nematodes and arthropod pests (Edwards et al. 2007). The nutrient content of vermicompost tea can vary depending on the source materials and brewing methods. Liquid vermicompost typically contains three essential plant nutrients: nitrogen, in the form of nitrate or ammonium (NO3 and NH4); phosphorus (P); and potassium (K). An analysis of vermicompost tea brewed at a 1:10 ratio revealed the following average nutrient concentrations: nitrate (NO3) at 77 ppm (parts per million); ammonium (NH4) at 3.7 ppm; phosphorus (P) at 18 ppm; and potassium (K) at 186 ppm. Methods for creating liquid extracts from vermicompost include: 1. Percolation: This involves passing water through vermicompost material to extract the soluble components. 2. Soaking: Vermicompost can be soaked in water for a period ranging from 1 to 7 days, allowing the leachate to form. These methods can be modified or enhanced in several ways: Aeration: Introducing aeration, such as bubbling air through the solution, can enhance the extraction process. Addition of Other Materials: Other organic or bioactive materials may be added to the mixture to enrich the extract. Incorporation of Organic Substrates: Organic substrates can be introduced to encourage microbial activity and nutrient release during the extraction process.

10.3 Vermimeal Vermimeal, also known as earthworm meal, is a feed product composed of processed earthworm biomass. It serves as a highly nutritious source of animal protein, essential amino acids, fats, vitamins, and minerals for livestock, poultry, and fish. To produce 1 kg of vermimeal, approximately 5.5 kg of fresh earthworm biomass with 18% dry matter content is required. It can be conveniently packaged in plastic bags

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and stored in a cool, dry location away from direct sunlight for up to 3 months. The proximate analysis of dry, pulverized earthworm-vermimeal reveals the following composition: 68% crude protein, 9.57% fat, 11.05% nitrogen-free extract, and 9.07% ash. Numerous research studies conducted on various livestock species, poultry, and fish have consistently demonstrated the positive impact of incorporating vermimeal or earthworm meal into their diets. This is unsurprising, as earthworms naturally serve as a nutritional food source for wild birds and other animals in their natural habitats.

10.4 Enriched Vermicompost An emerging trend in the field of vermicomposting involves the enrichment of nutrients and the cultivation of beneficial microbial populations within the vermicompost, ultimately resulting in improved crop growth and yield. This innovative approach, referred to as “enriched vermicompost,” combines vermicompost with natural minerals and micro-organisms, offering several advantages over traditional vermicomposting methods. Enriched vermicompost not only contains additional nutrients but also requires less production time. One notable benefit of this new type of compost is its flexibility, allowing for the customization of nutrient concentrations to meet the specific requirements of various plants and soils. To create this enriched fertilizer, vermicompost is produced using raw materials like farm manure and legume residues, which are then blended with natural minerals such as rock phosphate and mica powder. In addition to minerals, enriched vermicompost incorporates micro-organisms like Aspergillus awamori and Trichoderma viride. These micro-organisms play a crucial role in supplying and safeguarding fertilizers while aiding in the mineralization of elements essential for crop growth. Recent studies have explored the potential of enriching vermicompost with microbial inoculants, including bio-fertilizer organisms like Azospirillum brasilense and Rhizobium leguminosarum. These studies have sought to optimize the inoculum level and timing of inoculation during the vermicomposting process.

10.5 Pelleted Vermicompost Vermicompost is a valuable substance for enhancing the physical and chemical properties of soil. However, its widespread application faces challenges due to two key factors. Firstly, vermicompost typically contains a high moisture content and occupies a considerable volume relative to its weight, making transportation both challenging and costly. Secondly, the quality of vermicompost, including its nutrient composition, tends to vary, which hinders its consistent and efficient utilization. One effective solution to address these issues is the utilization of pellet technology in the production of compost. This method transforms vermicompost into convenient pellet forms, mitigating the challenges associated with moisture content and bulkiness, and ensuring a more consistent and manageable product for use.

References

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A pellet machine can be employed to convert composted manure into pellets with a diameter ranging from 0.5 to 1  cm. The machine, which was designed in 2007 by Nitin K. Tyagi from Meerut, Uttar Pradesh, India, operates manually and consists of several components: a hopper, a flat moving belt, a die for pellet formation, and a power transmission system. This machine can be operated by a single person. The underlying principle involves blending vermicompost with an appropriate binder, such as molasses. The mixture is loaded into the hopper, conveyed via the belt onto a flat surface in sheet form, and then passed through a pellet-­making die to produce a stream of pellets. While the concept of using a conveyor and die system to create conventional compost pellets is well-established, and it find its applications in chemical and pharmaceutical industries, the innovative aspect here is the adaptation of this concept for the production of “vermicompost pellets.” When pelleting is carried out without the addition of other materials, it becomes essential to carefully regulate the moisture content of the compost and control the rate at which the compost is supplied to the pellet-making section of the machine. Once the pellets are dried, they maintain their shape and integrity throughout storage and transportation. Importantly, these dried pellets occupy only 60% to 90% of the volume compared to raw compost. This reduction in volume means that less storage space is required, and the pellets can be evenly distributed across fields. When in pellet form, the gradual release of nutrients to plants occurs over an extended period, promoting sustained nutrient availability for crops.

References Ansari AA, Sukhraj K (2010) Effect of vermiwash and vermicompost on soil parameters and productivity of okra (Abelmoschus esculentus) in Guyana. Pak J Agric Res 23(3–4):137–142 Edwards CA, Arancon NQ, Emerson E, Pulliam R (2007) Suppressing plant parasitic nematodes and arthropod pests with vermicompost teas. Biocycle 48(12):38–39 Giraddi RS (2003) Method of extraction of earthworm wash: a plant promoter substance. In: VIIth National Symposium on Soil Biology and Ecology, Bangalore Rekha GS, Valivittan K, Kaleena PK (2013) Studies on the influence of vermicompost and vermiwash on the growth and productivity of black gram (Vigna mungo). Adv Biol Res 7(4):114–121 Saumaya G, Giraddi RS, Patil RH (2007) Utility of vermiwash for the management of thrips and mites on chilli (Capiscum annum) amended with soil organics. Karnataka J Agric Sci 20(3):657–659 Suthar S (2010) Evidence of plant hormone-like substances in vermiwash: an ecologically safe option of synthetic chemicals for sustainable farming. J Ecol Eng 36(8):1089–1092 Thangavel P, Balagurunathan R, Divakaran J, Prabhakaran J (2003) Effect of vermiwash and vermicast extract on soil nutrient status, growth and yield of paddy. Adv Plant Sci 16(1):187–190

Problems in Handling Vermicompost

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Handling vermicompost can sometimes present challenges. One common issue is the presence of unwanted pests, such as mites, which can disrupt the composting process and impact the quality of the vermicompost. Additionally, maintaining the right moisture level can be tricky, as overly wet or dry conditions can lead to problems like foul odors or slowed decomposition. Properly managing the pH level of the vermicompost is also essential, as an imbalance can hinder the growth of beneficial micro-organisms. Furthermore, the physical handling of vermicompost can be cumbersome, particularly on a large scale. The fine texture of vermicompost makes it prone to clumping, which can complicate distribution and application. Despite these challenges, addressing them through careful management and monitoring can help ensure successful vermicomposting and high-quality vermicompost production.

11.1 Temperature Both high temperatures and low temperatures can pose challenges for vermicomposting. When the temperature of the vermicompost bedding exceeds 29  °C, red wiggler worms tend to become inactive. To prevent this, it is advisable to place the composting bin in a shaded area when it is kept outdoors during the warmer seasons. Additionally, the moisture in the bedding can provide some natural cooling through evaporation, although during the summer, you may need to add more water to maintain this cooling effect. The main concern with heat is the potential for the bin interior to become excessively hot due to microbial activity. To mitigate this, it is beneficial to feed the worms smaller amounts of food on a regular basis rather than providing a large amount of food all at once. Generally, worms thrive in cooler weather, and their activity and reproduction tend to peak as temperatures cool in the fall and warm up in the spring.

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_11

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11.2 Aeration Ensuring sufficient airflow within the bin is a crucial aspect of its construction. To facilitate air circulation, it is advisable to create holes along the upper sidewalls of the bins. However, it is important to be cautious about drilling holes in the lid, as this can lead to water entering the bin during the rainy season. The type of bedding chosen also plays a role in air circulation. Coarser bedding materials like chopped leaves allow for better airflow compared to finer textures such as peat moss or shredded paper. Over time, as the composting process advances, the bedding tends to become finer in texture. This issue can be mitigated to some extent by periodically introducing fresh bedding into the mix. There are other methods to enhance aeration as well, including occasionally fluffing the bedding material, avoiding the use of excessively deep bedding (limiting it to a maximum of 30 cm), and being mindful not to overfeed or overwater the composting system.

11.3 Acidity (pH) The breakdown of organic materials generates organic acids, which can lead to a decrease in the pH level of the bedding soil. To address this issue effectively, it is recommended to incorporate several cups of finely ground limestone into the bedding mixture, along with an appropriate application of Zeolite. The use of limestone serves a dual purpose, as it helps in stabilizing acidity while also providing a valuable source of calcium for the worms. Alternatively, powdered limestone or dolomite limestone can also be considered as suitable options for pH management. It is important to avoid using baking soda due to its high sodium content.

11.4 Pests and Diseases Vermicomposting worms are generally resilient to diseases caused by micro-­ organisms. However, they are vulnerable to predation by specific animals and insects, with red mites being particularly problematic. Additionally, they can be affected by a condition known as “sour crop” due to environmental factors. Below, we provide a concise overview of the most prevalent pests and diseases. Ants: These minuscule insects pose a significant challenge as they not only consume the worm feed but also target young worms, leading to severe injuries. Ants are especially drawn to sugary substances, so mitigating this issue can be achieved by refraining from using sweet feeds in the worm beds. Alternatively, constructing a water channel around the bottom of the vermi-tank provides a long-term solution to the ant problem. Rodents: Worms are highly sought-after as a natural food source for various small animals, including rats. In the event, where rat enters the worm bed, there is a risk of losing a substantial number of worms in a short span. Rats and mice possess the capability to gnaw through plastic or wood effortlessly, and they require

11.4  Pests and Diseases

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minimal space to navigate across surfaces. Typically, this issue arises when utilizing open-air systems, especially in outdoor settings. To prevent such incidents, it is advisable to install a protective barrier, such as wire mesh, for the lids. Birds: While they typically aren’t a significant issue, if these creatures find your vermicomposting beds, they may become regular visitors with an appetite for worms. To address this, placing a lid on the tank or covering the material in open-air systems can effectively eliminate this problem. Additionally, these covers serve the dual purpose of retaining moisture and preventing excessive leaching during rainy periods. Old carpet can be repurposed for this use and proves to be highly effective in this regard. Centipedes: These insects have a preference for consuming compost worms and their cocoons. Fortunately, it appears that they do not reproduce extensively within worm beds or windrows, resulting in generally minor damage. However, if their numbers become problematic, one suggested approach to reduce their population is to thoroughly moisten the worm beds, without reaching a flooding level. This water application compels centipedes and other insect pests to surface, while the worms remain unharmed. Once on the surface, these pests can be eradicated using tools like a handheld propane torch or a similar method. Sour crop: This condition is attributed to poisoning due to an excessive protein presence in the bedding, which occurs when worms are overfed. When protein accumulates in the bedding, it undergoes decay, leading to the production of acids and gases. To prevent the occurrence of sour crop, farmers should avoid overfeeding and maintain regular monitoring and adjustment of the pH levels. Ensuring that the pH remains neutral or above will negate the necessity for these corrective actions. Mite pests: Insects are naturally drawn to worm beds because of the favorable combination of moisture and organic materials in this environment. When the bedding is not adequately maintained, an accumulation of acidity in the bedding soil can attract mites, as they tend to thrive in acidic and moist conditions. While small mite populations are typically found in all worm beds, issues may arise when their numbers become excessively high. In cases of elevated mite populations, worms may respond by retreating deep into their burrows, which can disrupt their feeding activities. Brown or white mites: White or brown mites typically have non-predatory nature and primarily consume decaying or wounded worms. Nevertheless, in situations of infestation, these mites can consume a significant portion of the available food within earthworm beds, consequently depriving earthworms of essential nutrients. Red mites: Initially, these mites manifest as small white or gray clusters, resembling mold. A closer examination under magnification would reveal these clusters containing juvenile red mites in different developmental stages. Adult red mites, in contrast, are smaller than white or brown mites and boast a vibrant red hue. They possess an egg-shaped body adorned with four pairs of legs. These red mites are recognized as parasites of earthworms. They attach themselves to the worm and derive sustenance from its coelomic fluid. Additionally, they have the ability to consume cytoplasmic fluids from egg capsules.

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Preventing the proliferation of mites and addressing their presence can be achieved through proper care of worm beds. Conditions typically associated with a high mite population include: (a) Excessive moisture: Beds that become excessively wet create an environment more favorable for mites than for the worms. To prevent excess wetting of beds, it is advisable to adjust watering schedules, enhance drainage systems, and regularly turn the bedding. (b) Overfeeding: Providing an excess of food can result in the accumulation of fermented feed in worm beds, causing a drop in pH levels. Feeding schedules can be adjusted and tailored to seasonal variations, and it is essential to maintain the pH of the beds at a neutral level (pH: 7) using calcium carbonate as a buffering agent. (c) High moisture or fleshy feed: Vegetables with high moisture content can attract a significant mite population in worm beds. The use of such feed should be limited, and if high mite populations persist, it may be necessary to discontinue the use of this feed until mite populations are brought under control. Removal of mites: Various methods have been proposed to eliminate mites from earthworm beds. However, whether the mite removal approach is physical or chemical, it will only yield temporary results unless there are changes in worm-bed management to create less favorable conditions for mites. The following techniques range from mild to more intensive measures: • Exposing the worm beds to sunlight for several hours, taking care to shield the earthworms from direct exposure. Reducing the amount of water and feed in the beds can further encourage the mites to vacate. • Placing moistened newspapers or burlap (jute) bags on top of the beds, which can be removed as mites accumulate on them. This process can be repeated until mite populations are significantly reduced. • Employing pieces of watermelon or potato slices on the worm beds, allowing the peels to be removed along with the mites. • Applying generous but non-flooding watering to the bed, compelling the mites to move toward the surface. Subsequently, the mites can be eradicated using a handheld propane torch. If necessary, this procedure can be repeated at 3-day intervals. • Utilizing light sulfur dusting to eliminate the mites. Alternatively, the bed can be moistened (as previously suggested), and sulfur can be added directly to the mite-infested areas. The application rate for sulfur should be approximately 2 grams per 0.93 square meters of bed. While sulfur doesn’t harm the worms, it may gradually increase the bed’s acidity. Although certain chemical pesticides have been historically used in worm beds, their biomagnification makes them an inadvisable choice.

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11.5 Odor Unpleasant odors can arise when compost lacks oxygen due to excessive food waste and excessive moisture within the bin contents. To address this issue, it is advisable to refrain from adding more food waste until the initial feed has been adequately broken down by the worms and micro-organisms. Additionally, gently stirring the entire contents of the bin can help facilitate better aeration. Check the drainage holes for any blockages, and if drainage remains insufficient, consider adding extra holes. In cases where worms appear to be migrating from the bedding, this behavior may not solely be due to soil moisture. It could also be attributed to the bedding’s acidity. To mitigate this, it is recommended to avoid incorporating citrus peels and other acidic foods into the bedding, as these can lower the pH of the bedding soil. To counteract this acidic environment, introduce a small amount of garden lime and reduce the addition of acidic waste materials. To effectively minimize unpleasant odors, consider the following steps: • Decrease the quantity of food waste being added. • Thoroughly stir the contents of the bin, paying special attention to the bottom. • Introduce paper if the bedding appears excessively wet or soggy. If the odors persist despite these efforts, the most effective solution may be to initiate a fresh start, using new bedding and a minimal amount of food scraps.

Importance of Application of Vermicompost in Cereal, Fruit and Vegetable Crops

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Vermicomposting is a process that harnesses earthworms to convert organic residues into a secondary product known as vermicompost, which serves as a valuable fertilizer for crop production (Dominguez 2004). This method offers an intriguing solution for addressing the growing volume of organic waste while simultaneously reducing the need for synthetic fertilizers. Additionally, the widespread use of composts represents an effective means of enhancing soil organic matter content, a critical factor for ensuring long-term soil fertility (Lal 2004; Dignac et al. 2017). Vermicompost is typically produced by epigeic earthworms that reside in the litter layer and the top few centimeters of soil, where they feed on fresh organic material. Among the various species available, Eisenia fetida and Eisenia andrei, as classified by Bouche (1977) within the Haplotaxida family of Lumbricidae, are the most commonly employed species for vermicomposting. This preference arises from their exceptional ability to ingest litter and reproduce at high rates. Vermicomposting offers a way to harness the benefits of earthworms’ services without directly increasing earthworm populations in the soil. In particular, vermicomposting enables us to: (i) Decrease the amount of organic waste, (ii) Enhance the stability of organic matter, (iii) Boost plant biomass production through various mechanisms, (iv) Raise the organic matter content in the soil, thereby reducing soil bulk density and enhancing the accessibility of water and mineral nutrients, (v) Exhibit hormone-like effects and mitigate the effects of pests and pathogens (Edwards et al. 2004. The use of vermicompost is well-recognized for its ability to improve crop yields by positively impacting the physical, chemical, and biological properties of the soil. When vermicompost is utilized, it results in crop growth and yield that are either slightly lower or equivalent to those achieved with mineral fertilizers in organic farming. Additionally, the application of vermicompost plays a pivotal role in promoting overall soil health, as illustrated in Table 12.1. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_12

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Table 12.1  Effect of vermicompost on growth and yield of cereal crops

Crop 1. Rice 2. Sugarcane 3. Cotton 4. Groundnut 5. Sunflower 6. Maize 7. Turmeric

Qty to apply/ acre 1 tonnes 1.5 tonnes 1 tonne 0.5 tonne

Time to apply After transplanting Last ploughing Last ploughing Last ploughing

1.5 tonnes 1 tonne 1 tonne

Last ploughing Last ploughing Last ploughing

12.1 Rice Crop According to Edwards (1998), vermicompost proves to be an excellent source of nutrients for rice cultivation. The application of vermicompost is considered superior to using chemical fertilizers. Sudhakar (2000) likewise indicates that the use of vermicompost derived from various agricultural waste materials substantially enhances rice yield attributes and overall crop yield when compared to the recommended application of NPK fertilizers (Table 12.2). 1. Sugarcane: The utilization of vermicompost (VC) has demonstrated a beneficial impact on all aspects of sugarcane production, including yield attributes, overall yield, and crop quality, when compared to the use of chemical fertilizers (Table 12.3; Ismail 1995). Vermicompost, a nutrient-rich organic material generated through the activities of earthworms, offers significant advantages for improving soil quality and has shown to enhance the yield and quality of fruit crops, as evidenced in Tables 12.4 and 12.5. Fruits cultivated with vermicompost exhibit increased attributes such as higher fruit production per hectare, greater fruit weight, and improvements in quality parameters such as total solids, total soluble solids, titratable acidity, ascorbic acid, and total chlorophyll content compared to fruits from plants receiving chemical fertilizer. Concurrently, the application of vermicompost contributes to reduction in soil acidity and enhances the levels of both macro and micro-nutrients (including N, P, K, Mg, Ca, S, Fe, Zn, B, and Al) in both the soil and plants. Numerous studies have indicated that the waste processed by worms and their excreted by-products, known as vermicast, exhibit a remarkable capacity to stimulate plant growth. It is evident that these substances have a positive impact on various aspects of plant development, including enhanced seed germination rates, improved seedling growth, and increased flowering and fruiting in major vegetable crops, as demonstrated in Table 12.6. The outcomes of this study revealed a notable improvement in the growth and yield of tomatoes (Table  12.7) with the incorporation of vermicompost, and this enhancement appears to be linked to the increased uptake of essential nutrients like phosphorus (P), potassium (K), iron (Fe), and zinc (Zn).

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12.1  Rice Crop Table 12.2  Effect of vermicompost on yield attributes and yield of rice Treatment Rec NPK Rice straw VC Sugarcane trash VC Water hyacinth VC LSD 5%

Productive tillers hill−1 7.5 8.25

Panicle length (cm) 18.64 20.44

1000-grain weight (g) 17.58 18.65

Grain yield (kg ha−1) 4090 5135

Straw yield (kg ha−1) 5294 6203

9.15

20.77

19.01

5551

6898

10.60

21.23

19.36

6315

7799

0.77

0.19

0.16

494

616

Source: Sudhakar (2000) VC applied at 5 t ha−1

Table 12.3  Effect of VC on yield attributes, yield and quality of sugarcane

Parameters No. of canes per hill Cane diameter (cm) Shoot length (m) Cane yield (t/ha) Brix (%) Pol (%) Purity (%)

Chemical fertilizer 6.00

Vermicompost 6.66

3.26 1.79 135.0 15.05 12.22 81.20

3.05 1.57 143.08 17.17 14.66 85.38

Source: Ismail (1995)

Table 12.4  Effect of vermicompost on fruit crops Crop Grape Citrus, pomegranate, ber guava Mango, coconut

Qty to apply per acre 1 tonne 2 kg per tree 2 kg per tree 5 kg per tree 10 kg per tree 20 kg per tree

Time to apply June–July At planting time and before flowering in 1–2 year old trees At planting time 1–5 year old trees 6–9 year old trees Trees older than 10 years

Table 12.5  Effect of vermicompost on the growth of Indian Orange Treatment Year No. of trees treated Avg weight of fruits (gm) Fruits production (t/ha) Source: Makode (2015)

Without vermicompost 2014 2015 500 500 115.8 125.7 25 23

With vermicompost 10 kg per tree 2014 2015 500 500 150.6 165.4 35 40

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Table 12.6  Effect of Vermicompost on vegetable crops Crop Onion, garlic, tomato, potato, bhendi, potato, bhendi, brinjal, cabbage, cauliflower Chilli Teak, red sandal-wood, mangium

Qty to apply per acre 1–1.5 tonnes 1 tonne 3 kg per tree

Time to apply Last ploughing Last ploughing At planting time

Table 12.7  Effect of vermicompost on growth and yield of tomato Vermicompost treatment (t ha−1) 0 5 10 15

No. of leaves plant−1 77.66 87.00 92.00 94.00

No. of blossom-end rot plant−1 3.75 1.50 0.75 0.50

Total yield (kg plant−1) 1.92 2.52 2.83 3.26

Source: Azarmi et al. (2008)

12.2 Uses of Vermicompost in Urban Areas Urbanization and industrialization have resulted in a rapid increase in the volume of solid waste, presenting one of today’s most pressing challenges in waste management. Various methods, such as landfilling, incineration, biogas conversion, recycling, and composting, exist for solid waste disposal. However, the excessive production of solid waste has led to inappropriate disposal practices, including their indiscriminate and poorly timed application to agricultural fields, resulting in water and soil pollution. Nevertheless, when managed appropriately, these organic wastes can find a valuable purpose in vermicomposting—a highly effective recycling technology. Vermicomposting enhances the quality of the end products by disinfecting, detoxifying, and enriching them with nutrients. This eco-biotechnological approach to waste management is both cost-effective and environmentally friendly. It harnesses the cooperative efforts of earthworms and micro-organisms to convert biodegradable waste materials into organic fertilizers.

12.3 Landfilling In developing nations, landfilling represents a cost-effective approach to waste disposal, where discarded materials are deposited into excavations, abandoned mining sites, excavated land, or borrowed pits. Landfilling stands as the conventional and widely practiced method for genuine waste disposal in numerous countries. This process entails land reclamation in low-lying areas by adding materials such as gravel, rubble, or loose substances.

References

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12.4 Incineration Incineration is a waste management procedure that encompasses the combustion of organic components found within waste materials. Incineration, along with other high-temperature waste treatment methods, falls under the category of “thermal treatment.” The incineration process transforms waste materials into ash, flue gas, and thermal energy. In certain instances, the thermal energy generated through incineration can be harnessed to produce electrical power.

12.5 Animal Feed Vermicomposting is a process that transforms organic waste into two valuable products namely organic fertilizer and worm biomass, which can serve as a protein source in animal feed. This approach directly converts waste into animal feed, making it an efficient cycle. Consequently, vermicompost can be characterized as a complex mixture consisting of earthworm excrement, well-humified organic matter, and a thriving community of micro-organisms. When incorporated into the soil or plant growth media, it has the remarkable ability to enhance various aspects of plant development, including germination, growth, flowering, fruit production, and the overall growth of a wide array of plant species. The notable boost in plant growth can be attributed to a range of both direct and indirect mechanisms. These include the provision of plant growth regulating substances and the enhancement of soil biological functions, which are biologically mediated processes. The utilization of this form of organic fertilizer holds substantial promise. However, recent studies have raised significant concerns regarding the universal applicability of these effects and have proposed a more intricate model to explain these impacts. The stimulation of plant growth may largely hinge on the specific biological characteristics of vermicompost, the particular plant species involved, and the conditions under which cultivation takes place.

References Azarmi R, Giglou MT, Taleshmikail RD (2008) Influence of vermicompost on soil chemical and physical properties in tomato (Lycopersicum esculentum) field. Afr J Biotechnol 7:2397–2401 Bouche MB (1977) Strategies lombriciennes. In: Lohm U, Persson T (eds) Soil organisms as components of ecosystems. Ecology Bulletin/NFR, Stockholm, pp 122–132 Dignac MF, Derrien D, Barre P (2017) Increasing soil carbon storage: mechanisms, effects of agricultural practices and proxies. A review. Agron Sust Dev 37:14 Dominguez J (2004) State of the art and new perspectives on vermicomposting research. In: Earthworm ecology. CRC Press, Boca Raton, pp 401–424 Edwards CA (1998) The use of earthworms in the breakdown and management of organic wastes. In: Edwards CA (ed) Earthworm ecology. CRC Press, Boca Raton, pp 327–354

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Edwards CA, Dominguez J, Arancon NQ (2004) The influence of vermicomposts on plant growth and pest incidence. In: Soil zoology for sustainable development in the 21st century. Cairo, Egypt, pp 397–420 Ismail S (1995) Earthworms in soil fertility management. In: Thapman PK (ed) Organic agriculture. Peckay Tree Crops Develpoment Foundation, Cochin, pp 78–100 Lal R (2004) Soil carbon sequestration impacts on global climate change and food security. Science 304:1623–1627 Makode PM (2015) Effect of vermicompost on the growth of Indian orange, citrus reticulatus with reference to its quality and quantity. Biosci Biotech Res Comm 8(2):217–220 Sudhakar G (2000) Investigation to identify crop wastes source to organics to sustain the productivity of rice based system. PhD thesis, Tamil Nadu Agricultural University, India

Beneficial Role of Vermicompost: Nutrient Content in Vermicompost and Success Stories

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On a global scale, the rapid trends of urbanization, industrialization, technological progress, and population growth have given rise to concerning issues related to the escalating production of solid waste. Coping with the management of such vast volumes of waste has become increasingly burdensome. Each year, the world generates over 1 billion tonnes of solid waste, a significant portion of which is disposed of in an unscientific and unsustainable manner, resulting in significant social, economic, and environmental costs. Effectively managing this monumental waste load is an immense challenge for humanity. Researchers worldwide are actively exploring novel, ecofriendly, and innovative technologies for waste management. Biological methods have emerged as a more suitable approach for waste treatment, as they have the capacity to recycle the diverse components of waste into valuable end products, all while being cost-effective. Vermicomposting stands out as a highly effective biological technique for waste management, involving a collaborative effort between microbes and earthworms to facilitate the degradation of waste materials. Vermicomposting represents a naturally occurring bio-oxidative decomposition process that takes place under mesophilic conditions and is further facilitated by the biochemical activities of micro-organisms. A variety of waste categories can undergo vermicomposting with the involvement of distinct earthworm species. Through the collaborative efforts of these earthworms and micro-organisms, waste materials are transformed into a fine, uniform, odorless, nutrient-rich, and humus-­rich organic material known as vermicompost. Within the digestive systems of earthworms, the waste substrate is broken down and its physicochemical properties are improved through enhanced decomposition of organic matter. Additionally, the micro-organisms residing in the earthworms’ guts play a vital role in the biochemical breakdown of the waste. Vermicompost serves as an effective plant growth promoter, boasting an array of advantages such as readily available plant nutrients, a thriving microbial community, humic compounds, growth-regulating hormones, and enzymes. Multiple research studies focusing on the utilization of vermicompost as an organic fertilizer

© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024 S. S. Walia, T. Kaur, Earthworms and Vermicomposting, https://doi.org/10.1007/978-981-99-8953-9_13

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have consistently demonstrated its ability to enhance crop growth and increase yields. Additionally, vermicomposting contributes to the establishment of a circular bio-economy by transforming waste into valuable products that play a pivotal role in promoting the sustainable development of a nation.

13.1 Beneficial Role of Vermicompost 1. Utilizing vermicompost as a soil amendment: Vermicompost not only introduces beneficial microbes and nutrients into the soil but also brings about positive changes in the physicochemical properties of the soil, promoting improved crop growth and development. Research has revealed that applying vermicompost at a rate of 20 tons per hectare over two consecutive years significantly enhanced soil porosity and aggregated stability (Ferreras et al. 2006). In a study by Azarmi et al. (2008) conducted in a tomato (Lycopersicum esculentum var. Super Beta) field, the application of 15 tons of vermicompost per hectare resulted in notable improvements (p