The Living Soil: A Lifetime Journey in Understanding It for Human Sustenance 9783031314124, 9783031314100

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SpringerBriefs in Environmental Science Kodoth Prabhakaran Nair

The Living Soil A Lifetime Journey in Understanding It for Human Sustenance

SpringerBriefs in Environmental Science

SpringerBriefs in Environmental Science present concise summaries of cutting-­ edge research and practical applications across a wide spectrum of environmental fields, with fast turnaround time to publication. Featuring compact volumes of 50 to 125 pages, the series covers a range of content from professional to academic. Monographs of new material are considered for the SpringerBriefs in Environmental Science series. Typical topics might include: a timely report of state-of-the-art analytical techniques, a bridge between new research results, as published in journal articles and a contextual literature review, a snapshot of a hot or emerging topic, an in-depth case study or technical example, a presentation of core concepts that students must understand in order to make independent contributions, best practices or protocols to be followed, a series of short case studies/debates highlighting a specific angle. SpringerBriefs in Environmental Science allow authors to present their ideas and readers to absorb them with minimal time investment. Both solicited and unsolicited manuscripts are considered for publication.

Kodoth Prabhakaran Nair

The Living Soil A Lifetime Journey in Understanding It for Human Sustenance

Kodoth Prabhakaran Nair Kozhikode, Kerala, India

ISSN 2191-5547     ISSN 2191-5555 (electronic) SpringerBriefs in Environmental Science ISBN 978-3-031-31412-4    ISBN 978-3-031-31410-0 (eBook) https://doi.org/10.1007/978-3-031-31410-0 © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 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 Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

India’s great President, late Dr. A.P.J. Abdul Kalam, launching the book, “ÏSSUES IN NATIONAL AND INTERNATIONAL AGRICULTURE” authored by Professor Kodoth Prabhakaran Nair, in Raj Bhavan (Office of the Governor of the State), Chennai, Tamil Nadu, India

I dedicate this book to Pankajam, my wife, a nematologist trained in Europe, who gave up her profession, and, instead, chose to be a home maker, more than four decades ago, when we had our son Dr. Kannan and our daughter Engineer Sreedevi. She is my all, the one who sustains me in this difficult journey, that life is.

It is also dedicated to the memory of my late parents, my father, Kuniyeri Pookkalam Kannan Nair, an illustrious Police Officer, who served the British Police, and who was decorated with the King George V medal for bravery and honesty, and my mother Kodoth Padinhareveetil Narayani Amma, daughter of the aristocratic Kodoth family of North Malabar, Kerala State, India, both of whom left me an orphan at a very young age, but, whose boundless love and blessings made me what I am today.

Photos of my father and mother

Further, I dedicate this book to the following, as well: Late Professor Dr. Ir. A.H. Cottenie, former Rector of the State University of Ghent, Belgium, and member of The Royal Academy of Science, Letters, and Fine Arts, one of the very few finest men I had the very good fortune to interact with, almost for three decades, who introduced me to the science of micronutrients when I joined him in February 1966 as a Post Doctoral Fellow, affiliated to the Belgian Ministry of Science and Culture. Late Professor Dr. Konrad Mengel, Director of the world renowned Institute of Plant Nutrition, Justus von Liebig University, Giessen, also, Curator of the Liebig Museum (Justus von Liebig was the “father of soil science,” who also propounded the “Law of Minimum” which states that if one specific essential nutrient is deficient in the soil while all the others are not, the plant output will be limited by this nutrient.), The Federal Republic of Germany, who first motivated me to embark on a research theme, when I

joined him in 1980 as a Senior Fellow of the world renowned Alexander von Humboldt Research Foundation, The Federal Republic of Germany, which finally has now led me to compile this book, by the grace of God, Almighty. Late Professor Dr. Horst Marschner, Director of the prestigious Institute of Plant Nutrition, University of Hohenheim, Hohenheim, The Federal Republic of Germany, who invited me to his institute, in 1993, to look into some serious field problems associated with zinc deficiency in wheat in Turkey, funded by a NATO project. I am keenly aware none of these three worldclass scientists, and, indisputably, wonderful human beings, are alive today, to look at what I have written. But, as a devout Hindu, I firmly believe that it is only the body that perishes, not the soul. From somewhere, I am certain, their souls would be blessing me for having undertaken this venture.

Acknowledgments

I am truly grateful to Ms. Rathika Ramkumar, Production Editor (Books), Springer Nature, and her team who have done a marvelous job in the production of this book. Ms. Margaret Deignan, Senior Editor, Springer Nature, for her support. I place on record a word of sincere appreciation for Ms. Sudha Elite Vanath, Project Manager of this Book, Springer, and her team, who did an efficient and expedient job of correcting the proof. Our son, Dr. Kannan Mavila, helped me a lot in the compilation of the photographs.

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Contents

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Introduction������������������������������������������������������������������������������������������������   1 1.1 The Challenge ������������������������������������������������������������������������������������   1 1.2 Soils and Sustainable Agriculture ������������������������������������������������������   3 1.3 Ensuring and Advancing Food Security����������������������������������������������   4 1.4 What Do the Above Data Prove?��������������������������������������������������������   4 1.5 What are the Basic Principles of Sustainable Soil Management?������   5 1.6 How Do We Reach Out? ��������������������������������������������������������������������   8 1.7 What Does the Concept of Soil Health Mean? ����������������������������������   9 References����������������������������������������������������������������������������������������������������  10

2

 Soils and Food Sufficiency������������������������������������������������������������������������  11 2.1 History’s Biggest Fraud: The “Agricultural Revolution”��������������������  13 2.2 What Is the Difference Between “Sustainable Development” and “Sustainable Agriculture”?����������������������������������������������������������  14 2.3 Sustainable Farming Systems of The Future��������������������������������������  15 2.4 What Should Be the Global Strategy to Ensure Sustainable Agriculture?����������������������������������������������������������������������������������������  15 2.5 Soils and Farming ������������������������������������������������������������������������������  16 2.5.1 What Is the Most Important Practical Significance of This Finding?����������������������������������������������������������������������  16 2.5.2 Calibrating the “Blanket” Recommendation Against the Buffer Power of Zn of These Soils������������������������������������  19 2.6 How Does Crop Yield Compare with Agronomic Inputs?������������������  19 2.7 What are the Practical Consequences of This Finding for the Cardamom Farmer? ����������������������������������������������������������������  21 2.8 How Do We Advance Food Security?������������������������������������������������  21 2.8.1 The Focus of This Book����������������������������������������������������������  22 2.9 “The Nutrient Buffer Power Concept” in Brief����������������������������������  23 2.9.1 Basic Concept ������������������������������������������������������������������������  23

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2.10 What Does the Above Equation Imply?����������������������������������������������  24 2.11 How to Precisely Quantify the “Buffer Power” of a Nutrient Ion Before Integrating Into the Computations?����������������������������������  25 References����������������������������������������������������������������������������������������������������  27 3

Future Imperatives������������������������������������������������������������������������������������  29 3.1 A Final Word��������������������������������������������������������������������������������������  31 3.1.1 A Timeline of Accomplishments��������������������������������������������  34 3.1.2 Some of the International and National recognitions ������������  36 3.1.3 Other Distinguished Recognitions������������������������������������������  37 References����������������������������������������������������������������������������������������������������  38

Appendix ������������������������������������������������������������������������������������������������������������  39

Chapter 1

Introduction The Concept of Soil: What Does the Word “Soil” Imply?

Abstract  The chapter discusses the challenges in soil management, and the concept of soil health. Keywords  Soil · Soil health · Genetically modified organisms

1.1 The Challenge During the World Soil Science Congress, held in Hamburg, The Federal Republic of Germany, in 1986, I referred to soil as “Soul of Infinite Life”, in the plenary session, to the mirth of the assembled audience. The intention was to substitute the words, “soul” (for the letter s), “of” (for the letter o), “infinite” (for the letter i) and “life” (for the letter l). Most in the assembled audience thought that soil was an “inert” matter, hence what life and what soul?. But, if one critically examines what goes round on the planet, one can then appreciate the intensity, depth and meaning of this phrase. In fact, it is soil that gives the very life and meaning to life on earth – be it humankind, animal or plant. When soils are ruined civilizations fall. The Roman Empire collapsed when it’s North African soils desertified. The same is true of the Thar desert in India, which once was a dense jungle. It is the mindless exploitation of the soil resources by the greedy man that leads to his ruination, and, the ruination of civilizations, at large. Soils are regarded by the International Policy Community as increasingly important in the world developmental issues, such as, food security, poverty alleviation, land degradation, and the provision of environmental services (Wood et al. 2000). Soils are a crucial component of terrestrial ecosystems and a determinant of their capacity to produce goods and services. Soils determine multifarious functions, such as, production, buffering, filtering and biological functions. Solar energy, carbon dioxide and nitrogen from the air, and nutrients from the soil are converted into plant products that provide animals and humans with food, fiber and biofuels. Soils hold water from episodic rainfall or irrigation as well as nutrients applied as organic inputs or mineral fertilizers, releasing them at rates plants can utilize for longer © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 K. P. Nair, The Living Soil, SpringerBriefs in Environmental Science, https://doi.org/10.1007/978-3-031-31410-0_1

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1 Introduction

periods of time. Soil biota decomposes organic minerals, cycle nutrients, and regulates gas fluxes to and from the atmosphere. Soils filter non-hazardous and toxic compounds through surface adsorption and precipitation reactions and largely determine the quality of terrestrial waters. Soils, therefore, deliver many of our basic needs and play a central role in determining the quality of the environment. Though we all, as soil scientists, will not dispute what has been written above, how is it that soil science has been relegated to the backyard, while others have made spectacular advances, or at least, others are noticed by people, at large, the world over, when we continue to be ignored by the world, at large? In fact, the most classic example, of late, is the science of genetically modified organisms (GMOs), be they of plant or animal origin. Notwithstanding the controversies surrounding them, there is aplenty, needless to ad, they have captured the attention of people all over the world, both scientific and lay. Ironically, none stops to think that, after all, even a genetically modified plant, say for instance a Bt cotton plant, cannot grow in outer space, but, needs a fertile soil to grow on. Tragically, the science of soil, is not even recognized as a “science,” in the sense others are, as for example, plant science or medicine, or even economics, which late Alfred Nobel refused to recognize economics as a science, and, hence kept it out of the ambit of the Nobel Prizes, for which he readily and happily provided money, though, much later the State Bank of Sweden instituted a Bank of Sweden Prize for economics, “in memory of Alfred Nobel”. Ironically even ow the Economics Prize is bandied around as a “Nobel Prize”, though, in reality, it is a State Bank of Sweden Prize in memory of Alfred Nobel for outstanding contributions in economics and social sciences! More often than not, my wife and two grown up children, an elder son, who is a doctor, and a younger daughter, who is an engineer, chide me as to where I have reached in life during the last almost five decade of professional commitments, dirtying my hands with soil, and thinking of the science of soil as a “science.” Their difficulty in trying to understand what I have done, and continue to do, is what in public awareness people call a “brand failure.” Our lack of visibility is related to our culture as “reductionist scientists,” operating largely within our limited scientific circles and with land users who utilize our knowledge of soil science and our extension services, but, sadly, and very disappointingly, fail to recognize the worth of our committed service to the well being of humanity. The take home message is that we soil scientists are the realproblem. But, we can become the solution by undertaking the kinds of synthesis research that are of direct use to policy makers and communicating to them in a way they readily accept it and put it to use. A classic example of global success is that of the Bt technology, where policy makers, starting from the United States of America to India (where the science of the Bt technology was totally unknown even up to as late as 2002), got the total involvement of the governments, and, so the policy makers who run them. Soil science has been brilliantly informed by reductionist physics and chemistry, poorly informed by biology, ecology and geography and largely uninformed by the social sciences (Swift 1999). In a survey of the global environment, The Economist magazine (6 July 2002) reported that leading experts could not reach a firm conclusion about the state of the environment, because, much of the information they needed was incomplete or missing

1.2  Soils and Sustainable Agriculture

3

altogether. This article went on to say that businessmen always say “What matters gets measured.” While soil scientists cannot be accused of not measuring soil properties, we are perhaps guilty in the lack of synthesis, integration, and interpretation of those measurements as they relate to environmental goods and services. We should certainly take on this challenge. The central focus of this book would be how “The Nutrient Buffer Power Concept” could be made to be an acceptable idea for the policy makers, so that it attains the status of a “brand.” This will, indeed, be the greatest service to soil scientists, as I firmly believe.

1.2 Soils and Sustainable Agriculture During the Nineteenth century and the first half of the twentieth century, when the global population was 38% of the 2006 level, the objective of soil management was to ensure agronomic productivity to meet the demand of a growing world population, roughly 2–3 billion. Demands on soil resources are different of a densely populated and rapidly industrializing world, as of to day, than what it was earlier. A country like India has already surpassed the, until now, population at 130 crores. Despite the highly chemical-centric extractive farming, euphemistically known as the “green revolution”, which resulted in a spurt in food production, which has plateaued or nose dived, of late, in India, and in the Punjab State, the “cradle” of Indian green revolution, things are in a state of complete disarray. There are thousands of acres, as for example in Punjab state, where even a blade of grass will not grow, without soil reclamation, at huge cost. Of the total of 328.73 million hectares of geographical area of India, more than 120.40 million hectares have now degraded soils, consequent to the green revolution. Punjab is the best example, where unbridled use of urea to prop up the “short-statured miracle rice and wheat varieties” took a heavy toll on soil resources. Ground water is polluted, water is no more potable. Indiscriminate use of pesticides and herbicides has led to the emergence of cancer. The Gurdaspur district in Punjab State is the best example – it has turned out to be the “cancer capital” of India. The chemically-centric, highly soil extractive green revolution has even contributed to global warming. The accelerating use of synthetic N fertilizers, like urea, to boost food production, is the primary driver for atmospheric concentration of nitrous oxide. The nitrous oxide which is released on urea hydrolysis escapes into the stratosphere where it entraps radiant heat causing increase in global warming. The nitrous oxide molecules stay put in the stratosphere/atmosphere for an average of 114 years before being removed by a sink or destroyed through chemical reactions. The impact of one pound of N2O on global warming is almost 300 times more than that of a pound of carbon di oxide. Nair (2019) has explained all these in his book “Combating Global Warming – The Role of Crop Wild Relatives For Food Security” (Springer Nature Switzerland AG, Nair 2019). According to the author, green revolution has contributed to as much as 35% to current global warming, especially in a country like India. Soil is at the center of all these questions. How do we manage soils for sustainable crop production is the crucial question:

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1.3 Ensuring and Advancing Food Security During the biblical era the global population was just about 0.2 billion which increased by 0.11 billion (to 0.31 billion) during the next 1000  years by 1000 AD. Subsequently, the global population increased a twenty-fold to 6 billion during the subsequent 1000 yeas by 2000 AD. By 2050 the global population is projected to grow to 9.4 billion (Cohen 2003). The most striking feature of this phenomenal population increase is that all the projected increase in global population will take place in the developing world, where, about 3.5 billion increase is foretold. Where would humanity go to feed the extra mouths? Among the developing countries of South Asia, India comes under sharp focus where the most of soil degradation has taken place, as explained above. This book chronicles the life time journey of the author in finding an answer to the above-mentioned crucial question. And, his revolutionary soil management technique, now globally known, as “The Nutrient Buffer Power Concept” is the focus of this book. Nutrient depletion and imbalance in soil adversely affect crop growth and its final yield. These are the most serious issues confronting soil scientists globally. More than 50% of a plant’s yielding capacity is decided by the nutrient factor, ad, it is the least resilient to management. This is why a critical understanding of the dynamics of soil nutrient bioavailability and how it can be intelligently managed becomes the central focus in this book. Tan et al. (2005) estimated the global nutrient depletion at the following rates: Nitrogen: 18.7 kg ha-1 year-1 Phosphorus: 5.1 kg ha-1 year-1 Potassium: 38.8 kg ha-1 year-1 The above rates are for 59%, 85% and 90% of harvested area in 2000. Tan and his co-workers estimated that the global annual nutrient deficit as follows: Nitrogen: 5.5 Tg Phosphorus: 2.3 Tg Potassium: 12.2 Tg

1.4 What Do the Above Data Prove? The above deficits cause a total loss of 1.136 million tons of food grains globally. Soil nutrient depletion is attributed to the following reasons: 1. Lack of or insufficient use of fertilizers 2. Unbalanced use of fertilizers 3. Losses caused by soil erosion In the well considered opinion of this author, among the three points mentioned above, the second point is of considerable importance. In this regard, one must

1.5  What are the Basic Principles of Sustainable Soil Management?

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debate the merits of the strategies which create and sustain positive nutrient and carbon budgets in managed ecosystems. Nutrient depletion, with the attendant adverse impacts on crop yield, occurs, when the nutrient removed (harvest, erosion, leaching, and volatilization) – the most important being the nitrous oxide emission consequent to urea hydrolysis, about which the author made a reference earlier in this chapter- exceeds the nutrient input. Also, when recycling, biological nitrogen fixation (BNF), input of animal manure, fertilizers, run on and aerial deposition. It is very important to note that nutrient depletion by indiscriminate mining through extractive farming has very adversely impacted farming and consequently crop yields in South Asia, (SA), Sub Saharan Africa (SSA) (IFDC 2006). There is nothing more than the highly chemically-­ centric extractive farming, euphemistically called the “green revolution” which illustrates this point very vividly. The need for “Carbon farming”: Carbon sequestration in terrestrial ecosystems, for instance, soils, trees, wetlands etc., and improving the quality of soil so that soils can be a be a net sink for CH4, and release less N2O is one of the most important issues which must be addressed by soil scientists, crop scientists, agronomists, foresters (both forest scientists and forest system managers), and wetland ecologists. Nair (2019) has eloquently argued on this aspect, focusing on “Crop Wild Relatives”, which is, yet, a huge untapped domain.

1.5 What are the Basic Principles of Sustainable Soil Management? In all, the following ten principles must be considered: Principle 1 In biomes and geographic regions, soil resources are unequally distributed. Highly productive soils in favorable climatic situations are finite in nature and, most often than not, situated in regions of high population density, as for example in a country like India, and have already been converted to managed ecosystems, for instance, crop land and grazing land, pasture, forest, and energy plantations. Principle 2 Most of the soils on the planet are prone to degradation by misuse or mismanagement of soils. Desperate situations lead to anthropogenic soil degradation, and, helplessness as in the case of resource-poor/marginal farmers, and small landholders. This is typical of the Indian situation. Human greed, short-sightedness and a lack of proper planning wishing quick results, which though welcome, in the short run, are but, worthless, in the long run.

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Principle 3 Decline in soil fertility and soil quality and accelerated soil erosion. More often than not, these soil degradations are accelerated by how unsuitable crops are grown than which crops should be grown. The productive potential of farming systems can only be realized when implemented in association with restorative and recommended soil and water management practices. Sustainable soil use depends on the judicious management of both in-site and off-site inputs. Indiscriminate and excessive tillage, irrigation, and fertilizer input can lead to as much or even more of soil degradation than none or minimal use of these technologies. The highly chemical-centric, extracting farming, euphemistically called the “green revolution” is the most illustrative example. Principle 4 Mean annual temperature increase and decrease in mean annual precipitation enhances rate of soil degradation. All of the other factors remaining constant, soils in hot and arid regions are more prone to soil degradation and desertification than those in regions which are humid and cool. However, soil mismanagement can lead to desertification even in arctic climates, for instance, in Iceland. Principle 5 Soil can either be a source or sink of greenhouse gases, such as, methane (CH4), CO2 and N2O, depending on land use and soil management. Soil is a sink of atmospheric CO2 under those land use and management systems which create a positive C (carbon) budget and gains exceed losses (see following Fig. 1.1). Soil is a source

Fig. 1.1  Sustainable agriculture

1.5  What are the Basic Principles of Sustainable Soil Management?

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of atmospheric CO2 when the ecosystem C budget is negative and losses exceed the gains (see Fig. 1.1). Soils are a source of radiatively active gases with extractive farming (read “green revolution”), which create a negative nutrient budget which degrades soil quality (as has widely taken place in Punjab State, India, consequent to the “green revolution), and, a sink with restorative land use and judicious soil management practices, especially fertilizer management, which create positive C and nutrient budgets and conserve soil and water, while improving soil structure. This is where the relevance of “The Nutrient Buffer Power Concept” comes into great scientific relevance. Principle 6 The most important fact to remember in farming is that soils are non-renewable assets over a human time frame of decadal and generational scales, which are, of course, renewable, but, on a geological scale, conforming to a centennial/millennial time frame. With burgeoning world population, which scientists project at 10 billion by 2100 AD, restoration of degraded and desertified soils over a centennial/millennial time frame is next to an impossibility. The heavy human demands for food on this non-renewable and if I may add, an invaluable global asset, such as soil, a gift of God, Almighty, indeed, it becomes extremely imperative that our approach to soil management must be visionary, not for short term gains, but, with long term benefits for all life – human, animal and plant. Principle 7 Both natural and anthropogenic perturbations are a test for the resilience of the soil. This, of course, depends on the physical, chemical and biological processes that take place in the soil substrate. Benevolent physical and chemical processes enhance soil’s resilience. And this happens only under favorable soil physical conditions, such as, optimum/good soil structure, tilth, aeration, water retention, transmission, and edaphological conditions, such as, soil temperature. Principle 8 Soil organic matter restoration rate of the soil organic pool is extremely slow. Its depletion, more often than not, is so very rapid. Global deforestation for human greed is the best example. Principle 9 Both an architectural design and soil structure are similar to each other, inasmuch as functional aspects conform to stability, and continuity of macro, mesopores (mesopores or medium pores which hold the main plant available water. They consist of both moisture and air. The more the mesopores are in the soil, the better it is for plant growth and no waterlogging takes place, due to heavy rainfall or unbridled irrigation), and micropores, which are the sites of physical, chemical and biological processes, which support soil’s life supportive functions. Sustainable soil management systems, which are site-specific, enhance greatly soil stability and continuity of pores, specified above, and voids, over a time frame, also, under diverse land use systems.

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It is, thus, the superb ingenuity and foresight of the “soil manager” – be it a soil scientist/crop scientist/biologist- that ensures the premier dictum of this author of soil as a “soul of infinite life”, not merely to be handled as an “inert” material, at will, for personal gain and profit, but, as an invaluable asset for the benefit of all life – man, animal and plant – until eternity. Principle 10 Ensuring and enhancing a trend in net primary productivity per unit of off-farm inputs, such as fertilizers, and water, along with improvement in soil quality and ancillary ecosystem services, such as enhancement of carbon pool, improvement in quantity and quality of fresh water and renewable water resources, with concomitant increase in biodiversity, being the prime focus in intelligent soil management. As said in the initial section of this chapter, soil is an invaluable asset, gift of God, Almighty, and the “soul of infinite life”. It is imperative that the current generation hands over the global soil resources, to the generation next, in as much a good state as possible, as was inherited, from the past generation. If we fail, the fate of humankind will be similar to that of civilizations which lost its perspective, like the Mayan, Incas, Indus and Mesopotamian. Attention to the revolutionary soil management technique, “The Nutrient Buffer Power Concept”, explained in this book, is a clarion call to this urgent need.

1.6 How Do We Reach Out? Traditionally, soil is known to fulfil the following three most important functions: 1. As a medium of plant/crop growth 2. As a foundation for civil structures (in fact more than 5000 years ago, soils acted as a foundation/support for human predation) 3. As a source of raw materials for the different industries In my opinion, during the current twenty-first century, and, possibly beyond, function of the soil/soil resources must include the following functions, as well: 1. To mitigate the adverse environmental consequences of climate change though carbon sequestration both in terrestrial and aquatic ecosystems. Act as an efficient repository for Crop Wild Relatives to ensure food security (Nair 2019). 2. The purification of water through filtration and denaturing of the different pollutants 3. Disposal of both urban and rural wastes in such a manner that these do not pollute air nor contaminate water sources 4. Store the different germplasms, both plant-originated and microbial-originated, the latter which can be used to combat both plant and other animal diseases 5. To act as a reservoir to archive, human, plant and animal history 6. To act as a support, being a reactor of both physical and chemical processes

1.7  What Does the Concept of Soil Health Mean?

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7. To act as a regulator of global warming, by intelligent soil management, especially through sensible and sustainable use of synthetic fertilizers like urea, which when used in an unbridled manner contributes to global warming through emission of nitrous oxide(N2O). As much as 35% of global warming is attributable to this phenomenon (Nair 2019) 8. To act as a strategic entity in national and international affairs to give peace a chance 9. To awaken the feeling in oneself that without soil there is no life on planet earth and keenly instill this thought as a moral responsibility to “treat the soil well” as a “living system” and not as an inert or dead matter By the end of twenty-first century, the world has to absorb an extra 3.5 billion mouths. These extra mouths will be concentrated in the densely populated nations of the South Asian Continent, such as India, Pakistan and Bangladesh and Africa. This would urgently require that we, scientists, revisit the earlier enunciated principles of “sustainable agriculture”. Specifically, these areas of concern are: 1. Maximize crop productivity per unit area, input of synthetic fertilizers, irrigation water, input of water – the dictum must be “more crop per drop”- and not the colossal wastage of water, as one can see in States like Punjab, in India, where the unscrupulous politicians to garner public support/vote during elections, promise free electricity to the farmers to pump out ground water, to sustain the green revolution, resulting in dangerous lowering of water table. 2. Off-farm inputs should be optimal 3. Enhance household (farmers, especially)income from off-farm employment, value addition of farm products, and, where occasion/situation permits, take recourse to carbon trading 4. Enhance the quantity and quality of water at the farm level 5. Create possibilities, especially for uneducated rural women, for education 6. Instill the possibilities of providing clean cooking fuel at the farm level for poor women 7. Ensure food security for the rural folk until the following harvest 8. Encourage organic farming wherever possible, and, ensure fair market price for the products of organic farming 9. Educate the populace on the great importance of soil as a source of sustenance for life – human, animal and plant

1.7 What Does the Concept of Soil Health Mean? Soil health is the continued capacity of soil to function as a vital living ecosystem that sustains plants, animals and humans, and connects agricultural and soil science to policy, stakeholder needs and sustainable supply- chain management. Historically, soil assessments focused on crop production, but, today, soil health also includes the role of soil in water quality, climate change and human health. However,

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1 Introduction

quantifying soil health is still dominated by chemical indicators, despite growing appreciation of the importance of soil biodiversity, owing to limited functional knowledge and lack of effective methods. In this perspective, the definition and history of soil health are described and compared with other soil concepts. There are many ecosystem services provided by soils, the indicators used to measure soil functionality and their integration into informative soil-health indices. Scientists should embrace soil health as an overarching principle that contributes to sustainability goals, rather than only a property to measure.

References Cohen JE (2003) The human population: next half century. Science 320:1172–1175 IFDC (2006) African soil exhaustion. Science 312:31 Nair KPP (2019) Combating global warming – The role of crop wild relatives for food security. Springer Nature Switzerland AG Swift MJ (1999) Integrating soils, systems and society. Nat Resour 35:12–20 Tan ZX, Lal R, Wiebe KD (2005) Global soil nutrient depletion and yield reduction. J Sustain Agric 26:123 Wood S, Sebastian K, Scherr SJ (2000) Pilot analysis of global ecosystems: agroecosystems. International Food Policy Research Institute/World Soil Resources Institute, Washington, Washington, DC

Chapter 2

Soils and Food Sufficiency

Abstract  The chapter, at length, discusses the fundamental aspects of nutrient bio availability, with specific reference to Phosphorus and Potassium, among major nutrient nutrients, and Zinc among micronutrients. The basic concepts, based on thermodynamics, is the core of the discussion. Keywords  Buffer power · Thermodynamics · Diffusion · Phosphorus · Potassium · Zinc Advances in Agronomy, is the magnum opus of agricultural science, the most prestigious publication, a book series published by Academic Press -Elsevier combined, where highly reputed scientists are invited to publish peer-reviewed chapters, with an impact factor of 7.81 and an h-Index of 125, a first rate resource series book, to which I had the rare privilege of being invited to contribute seven chapters, may I add, in all humility, a world record at that, during the last three decades. It is popularly known as the “Bible of Agricultural Sciences”. Roy W. Simonson, a distinguished soil scientist, many decades ago, in one of early editions of the book series, wrote a chapter on the “Concept of Soil”. In the chapter he noted “Someone has said that the fabric of human life is woven on earthen looms – it everywhere smells of the clay”. Indisputably, this “fabric of human life” has dramatically changed during the past many millennia. Boul (1994) went on to add “this fabric of human life will always be linked to soil, which is the pragmatic, the reality, that dictates much of what societies can do”. I would call soil the “Soul of Infinite Life”. A unique gift, that God Almighty, has gifted to man, animal and plant. Without soil there is no life. That is why I have appropriately titled this book “The Living Soil”. Soil can be termed as a “thin mantle over the land surface”. This thin mantle has served varied purposes. Before the beginning of the “Agricultural Revolution”, more than 5000 years ago, this thin mantle was the surface – the physical support – for the predatory man – the hunter and gatherer. Through time, man has metamorphosized from predation to “settled farming” – the precursor of modern agricultural revolution. Though the mode of tending to the plant/crop changed, the basic instinct © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023 K. P. Nair, The Living Soil, SpringerBriefs in Environmental Science, https://doi.org/10.1007/978-3-031-31410-0_2

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of predation has remained. How else can one explain the disdain and callousness with which man treats soil? The common man still considers soil as an “inert dirt”. Where the soil was abused, civilizations collapsed. The Roman Empire collapsed when its North African soils  – the granary for the Roman Empire- desertified. Nearer home in India, the present day Thar desert, which is partly in the State of Rajasthan, and partly in Punjab and Sindh Provinces of East Pakistan, is a grim reminder of this catastrophic abuse of soil. Though the change in habits of man from predation, as a hunter and gatherer, to stationary farming, what may be called the “agricultural revolution”, took place in pre Christian times, focussing on the inevitability of a proportionally smaller land surface supporting a larger human population, it is only in recent times that one has witnessed the magnitude of the impact of this shift in attitude on human existence. Much land has degraded and become unsuitable for farming during the last one century. The 1992–93 United Nations World Resources Report (Stammer 1992) on the status of global soils s contains very alarming conclusions. More than 10 million hectares of the best global farm lands have been very badly ruined by human activity since World War II which is almost impossible to reclaim, or can only be reclaimed at great cost. A classical example is that from India, where in the State of Punjab, the “cradle of Indian green revolution”, where thousands of hectares have been so badly ruined and degraded that not even a blade of grass will grow, without huge investments in reclamation efforts. Globally, more than 1.2 billion hectares, of which many are now so badly degraded due to the highly chemical-centric extractive farming, euphemistically called the ‘green revolution” can only be restored to normalcy only at a very great cost. The situation in Punjab, in India, illustrates this point lucidly. This enormous loss in soil capability would result in huge loss in food production in the coming two to three decades. The vulnerable would be the citizens of the disadvantaged African and Asian nations. Two-thirds of the seriously eroded and degraded soils are on the African and Asian continents. About 25% of the cropped land in Central America is moderately to severely damaged. In North America, this is a small percentage, just about 4.4%. From the onset of the so-called green revolution, food production has declined dramatically in 80 developing countries during the past decade. For this, soil degradation has been the principal cause. Nearly 40% of the world’s farming is done on very small parcels of one hectare or even less (Robison et  al. 1981). Sadly, ignorance and poverty characterize this pathetic situation. Yet, emphasis on agriculture has been confined mostly to large-­ scale farming. Huge farming, has been the order of the day for many decades. Even the “lebens raum”(living space) concept of the master military strategist, Adolf Hitler, had an echo in the inevitability of this modern day fact. What else can justify his ruthless conquest of vast territories of land, or the world’s soils? The basic premise that soil would continue to be the medium of plant/crop growth would continue for an indefinite length of time in spite of all the complexities of modern day soil science and management practices of soil. The burgeoning global population would need an enormous quantity of food to feed itself. Hydroponics/Soilless culture/Nutri culture/Tank farming cannot be a reliable

2.1  History’s Biggest Fraud: The “Agricultural Revolution”

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answer to this most difficult question. Only soils can sustain this enormous task. It is becoming increasingly clear that the earlier views of soil merely as “a supportive medium” is giving way to “managerial concepts” of this supportive medium. Even here, much of our managerial ideas about soil are still rooted in twentieth century concepts about soil. The highly chemically-centric soil extractive farming, of the 1960s to mid 1970s euphemistically called the “green revolution” has given way to the “sustainable agriculture” practices of the 1980s. The above scenario clearly indicates that neither the highly soil extractive and chemical-centric “green revolution” nor the “sustainable method”, as currently practiced, will ensure sustainable food production in the coming decades. Most of the factors of crop production, such as, more reliance on biological processes by adopting genotypes to adverse soil conditions, enhancing soil biological activity and optimizing nutrient cycling to minimize external inputs, such as fertilizers, and maximize their efficiency of use, have focused on the “sustainable” umbrella which will only partially meet our crucial objective of enhancing, dramatically, food production. And, add to this dismal picture, the adverse impact of climate change, principally global warming, on food production. Nair (2019) has clearly elaborated on this crucial aspect. It is very important to remember that the core factor in the food production chain is the “nutrient factor” as more than 50% of a crop/plant’s productive capacity is decided by the nutrient factor. Unless one targets to enhance the true efficiency of nutrient use, one cannot hope to fully exploit a crop’s full productivity. “The Nutrient Buffer Power Concept” effectively addresses this question.

2.1 History’s Biggest Fraud: The “Agricultural Revolution” For 2.5 million years humans fed themselves by gathering plants and hunting animals that lived and bred without human intervention. Homo erectus, Homo ergaster and the Neanderthals plucked wild figs, and hunted wild sheep without deciding where fig trees would take root, in which meadow a herd of sheep should graze, or which billy goat would inseminate which nanny goat. Homo sapiens spread from East Africa to the middle East and then to Europe and Asia, and, finally travelled to Australia and America- but, everywhere they went, Sapiens too continued to live by gathering wild plants and hunting wild animals. Why do anything else when your lifestyle feeds you and amply supports a rich world of social structures, religious beliefs, and political dynamics? This was the mindset of the early man. All this changed when Sapiens began to devote almost all their time and effort to manipulating the lives of a few animal and plant species. From sunrise to sunset humans sowed seeds, watered plants, plucked weeds from ground and grazed sheep in prime pastures. This work, they thought, would provide them more fruit, grain and meat. It was a revolution in the way humans lived  – the so-called “Agricultural Revolution” – history’s biggest fraud.

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2.2 What Is the Difference Between “Sustainable Development” and “Sustainable Agriculture”? It was the Brundtland Commission in 1987 that, at first, defined what “sustainable development” is, as per the directive of the World Commission on Environment and Development. In retrospect, it can be said, that one of the principal reasons behind this initiative was triggered by the highly soil extractive and chemically – centric farming, euphemistically called the “green revolution”, which has even contributed to as much as 35% to global warming (Nair 2019). This concept was subsequently taken forward by the United Nations Conference on Environment and Development at the Earth Summit, Rio de Janeiro, in Brazil, in 1992. From that time onwards, sustainable development became a key issue/key word in political and scientific bodies, for example, Intergovernmental Panel on Climate Change (IPCC, ipcc.ch), the Millennium Ecosystem Assessment, millenniumassessment.org), and, more recently, the Grenelle de l’ Environnement in France (legrenelleenvironnement.fr.). The concept of sustainable development is well accepted by a large public, globally, on account of the fact it has succeeded in defining global stakes involved, but, sadly, it is very vague about the practical manner in which those high stakes should be or could be attained. It would not be out of place to mention, in this context, that a global summit on global warming was organized by Mr. Antonio Guterres, United Nations Secretary General, in New York, on September 23, 2019, for the benefit of all Heads of the State. A book authored by me titled “Combating Global Warming – The Role of Crop Wild Relatives For Food Security” was launched during this global summit (Nair 2019). The definition of sustainable agriculture is varied, depending on the specific organizational imperatives and also depending on the author’s own focus. Some authors consider sustainable agriculture as a set of managerial strategies addressing the main societal concerns about the quality of food that it produces or the protection of the environment (Francis et  al. 1987), whereas some others focus on the ability of the specific agricultural systems practiced to maintain crop productivity over a long period of time (Ikerd. 1993). Yet, some other researchers’ focus on one main factor of sustainability, namely, flexibility, which is the adaptive capacity of agriculture to future changes. On the whole, all investigators agree on the need to ensure the following factors: 1. Environmental 2. Economic 3. Social Simply put, the specific yardstick for a sustainable agricultural system is, whether it can sustain itself over a long period of time. Nair (2016) has pointed out that the primary requisite of sustainability should be to ensure that the nutritional aspects, especially through the external application of synthetic fertilizers, must be, maximal in utility, maximal in terms of farmers’ economy and least environmentally hazardous. His focus has been, primarily directed, over the great environmental,

2.4  What Should Be the Global Strategy to Ensure Sustainable Agriculture?

15

soil – related, hazards, for instance, the huge land degradation, that occurred, during the highly chemical-centric and extremely soil extractive farming, euphemistically called the “green revolution”.

2.3 Sustainable Farming Systems of The Future Following the Second World War, the policy makers, especially in the Western Hemisphere, adopted a farming system, where the emphasis was to increase food production rapidly. The “Land Grant Pattern” which was put in place by the United States of America was propelled, by the development of the high yielding, dwarf, “miracle varieties” of wheat and rice, the former developed at CIMMYT (International Maize and Wheat Improvement Center) at El Batan, near Texcoco, State of Mexico, formed in 1943, 1966 and officially established in 1971, as a joint venture between the State of Mexico and Rockefeller Foundation, and the latter developed at the International Rice Research Institute at Los Banos, Philippines, with the help of The Rockefeller Foundation and with the support of the Philippine Government. Though for a time, just about a decade at the most, the “miracle” dwarf wheat and rice germplasms exhibited a high yield potential, responding to high synthetic fertilizer inputs, especially nitrogenous, such as urea, soon this positive impact was rapidly nullified by the huge negative impact on the environment, among which, soil degradation was the most dangerous and ominous. In India, alone, of the 328.73 million hectares of geographical area, more than 120.40 million hectares have degraded soils, post the “green revolution”. Additionally, some of the popular wheat and rice varieties fell prey to dreaded plant diseases, such as, rust on wheat and blight on rice, In addition to these, widespread attack of plant hopper (Brown Plant Hopper, BPH), nearly decimated the rice crop in South Asia, especially in India. This pulled down the yields drastically. It can all be traced to the “alien blood” these genotyes carried.

2.4 What Should Be the Global Strategy to Ensure Sustainable Agriculture? The underlying principle in a global strategy to ensure sustainable agriculture is, first to identify, what the critical issues are, and, follow them up with procedures based on sound established scientific facts. Any forward measure must be based on a rethought, taking into full account, as to what went wrong earlier, and then decide as to what suits the society best, at large, in the future. No matter how sound the methodology is, scientifically, if it does not serve the society’s best hopes and aspirations, such approaches will fall by the wayside during the march of time. That has been the story of the highly soil extractive and hugely chemical-centric farming,

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euphemistically called the “green revolution”. Indeed, most failures of “extractive farming”, (read the highly chemically-centric farming euphemistically called the “green revolution”) are closely linked to its economic model. There are fundamental contradictions among several aims assigned to agriculture. For instance, producing more and cheaper food products without polluting soils. And, producing more fruits and vegetables without pesticide residues and without visual pest damage appear to be unrealistic aims. The global strategy relies in rethinking the role of agriculture in our society, as shown by the new trends in agroecology (Gliessman 2006). This approach focuses on the crucial fact that sustainability cannot be reached solely through farming systems, but, must also involve the food system, the relationship between the farm and food consumption, and the marketing networks. For instance, investigators examining the relationships between production and marketing highlighted the interest in alternative food networks focused on the local production (Lamine and Bellon 2008). Hence, the global strategy requires networking with interdisciplinary systems. In whichever approach one moves forward on the question of agricultural sustainability, it is the soil, the “living” mass, the “thin mantle over the land surface”, that plays the central role. And, the “nutrient factor” is the key to sustainability. Both native fertility, and, added fertility, through synthetic fertilizers, is governed by thermodynamic factors. It is a thorough understanding of this aspect that makes “The Nutrient Buffer Power Concept” unique. And, that is the principal focus of this book.

2.5 Soils and Farming Goals of soil management during the nineteenth century and first half the twentieth century when global population was just 38% of the 2006 level, was to maintain agronomic productivity to food demands of about 3 billion inhabitants, However, when societal pressure increases because of higher energy demand, water, wood products, and, land for urbanization, in addition to food demands of a burgeoning global population, one’s focus has to appropriately shift. To a great extent, solutions to these issues lie in the sustainable management of global soil resources. Figures 2.1 and 2.2 graphically illustrates the interconnectedness of the various factors involved.

2.5.1 What Is the Most Important Practical Significance of This Finding? Black pepper (Piper nigrum) is the economic mainstay of Kerala State, India. It is very susceptible to the Phytophthora fungal attack (“Quick Wilt”) which can devastate an entire pepper plantation in just 1  week, hence named as “Quick Wilt”

2.5  Soils and Farming

17

Fig. 2.1  Properties, processes and practices which govern soil degradation and resilience, and sustainable management

Fig. 2.2  A positive C (and nutrient) budget is essential to C sequestration

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2  Soils and Food Sufficiency

disease. This author had observed that the disease is Zinc-mediated, a deficiency of soil Zn triggers the disease. Hence, this investigation was taken up in Kerala State (Calicut District), where the Indian Institute of Spices Research (IISR) is situated. IISR has its research station on Black pepper in Peruvannamuzhi. And, the “blanket recommendation” to all pepper growing farmers is to apply 25 kg Zinc sulfate per hectare. It should be importantly noted that this “Blanket” recommendation emanates from the research carried on Black pepper in the Peruvannamuzhi region where the IISR pepper research station is located. Soils in the Peruvannamuzhi region are atypical Black pepper growing soils. Hence, the recommendation emanating from the research carried out here will not be applicable for the entire Kerala State, and this is clearly substantiated by the data in Tables 2.1 and 2.2, where the deviation was 66% in actual vine yield from the farmers’ fields as compared to the targeted yield. The Zinc sulfate fertilizer is a very expensive one in India

Table 2.1  A global summary of the effectiveness of the “Buffer power concept” Nutrient P uptake Zn uptake P uptake K uptake Zn uptake K uptake Zn uptake Dry matter production

A 0.393* 0.290 0.170 0.180 0.015 0.251 0.780 0.740

B 0.887*** 0.812*** 0.770*** 0.780*** 0.784*** 0.437*** 0.860*** 0.780***

Test crop Summer rye (Secale cereale) Maize (Zea mays) White clover (Trifolium repens) White clover (Trifolium repens) Wheat (Triticum aestivum) Cardamom (Elettaria cardamomum) Black pepper (Piper nigrum) Black pepper (Piper nigrum)

Test country West Germany Belgium Cameroon Cameroon Turkey India India India

Note: * = Significant at 5% confidence level *** = Significant at 99.99% confidence level A = Using Standard soil testing procedure B = Integrating the “Buffer Power” of the specific nutrient in the statistical computations Important Note: Note the change from a negative correlation with regard to dry matter production turning into a positive and highly significant correlation when the Zn “Buffer Power” is integrated into the computations. The standard soil test used here was the universally employed DTPA extraction. This simply proves the futility of this universally employed soil test for Zn in Indian (Kerala) soils.

Table 2.2  Black pepper (Piper nigrum) yields from farmers’ fields weighted against the Zn buffer power Region in Kerala State, India Peruvannamuzhi Thamarasseri

Yield (kg/vine) Targeted 0.241 0.490

Deviation (%) Actual 0.401 0.487

+ 66 +0.6

Note: Target weighting accomplished against the maximum pepper vine yield harvested from the Ambalavayal region. This region is the most productive for Black pepper growing. Note the remarkable closeness between the Black pepper vine yield from the Thamarasseri region in targeted yield and actual yield; while in the case of the Peruvannamuzhi region the deviation is 66%

2.6  How Does Crop Yield Compare with Agronomic Inputs?

19

(a kilogram of zinc sulfate costs in excess of US $ 1, and, translated into INR (Indian Rupee) it would be about INR 80, which is a lot money for a marginal Black pepper growing farmer. In other words, the official “Blanket” recommendation of zinc sulfate would involve an expenditure of close to INR 2000/ha which is quite a lot of money for a marginal Black pepper farmer of Kerala. Stopped Here

2.5.2 Calibrating the “Blanket” Recommendation Against the Buffer Power of Zn of These Soils The Zn buffer power of the experimental soils are given in the following table (Table 2.3) below. The soils of the Ambalavayal region have a Zn buffer power of 3.0358 as compared to the soils from Peruvannamuzhi region. In other words, Ambalavayal soils have the potential, which is nearly more than four-fold to supply Zn as compared to the soils from the Peruvannamuzhi region. In practical terms, this would imply that the Ambalavayal soils would only require 25% of the total quantum of Zn applied to Peruvannamuzhi soils. Translated into the practical recommedation, it would imply that the Ambalavayal soils would only require about 5  kg of Zinc sulfate, when the Peruvannamuzhi soils require 25  kg Zn sulfate/ha. In the case of Thamarasseri soils, the amount required would be 50% of the “Blanket” recommendation, that as, 12.5 kg. To sum up, this unquestionably proves the fallacy of the official “Blanket” recommendation emanating from the Indian Institute of Spices Research, Calicut, Kerala State, India, for the Black pepper farmers of the State.

2.6 How Does Crop Yield Compare with Agronomic Inputs? Though strategies to improve soil quality might be built on traditional knowledge of farming, they must be strongly based on proven scientific knowledge. Crop yields in developing countries are strongly related to inputs, especially, fertilizers’ input and irrigation water. Though the latter is controlled by local factors, like sufficient Table 2.3  Zn buffer power of the experimental soils

Northern Kerala Region Peruvannamozhi Thamarasseri Ambalavayal

Zn buffer power 0.7824 0.9304 3.0358

Source: Nair 2016. The nutrient buffer power concept for sustainable agriculture, Notion Press, Chennai, India

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electricity to pump ground water, (like free electricity provided by the local government to the farmers to pump water, which led to overexploitation of ground water, leading to dangerous lowering of water table, as has happened in the State of Punjab, in India, to sustain the green revolution), the former is decided by the quality and quantity of external inputs of synthetic fertilizers. With the world average of milled rice at 4 Mg ha−1, India compares rather poorly, at 3 Mg ha−1, while in USA, it is 8.5 Mg ha−1. Similarly, for the world average maize yield at 5 Mg ha−1, the Indian average yield is, indeed, a very poor comparison, at 2 Mg ha−1, while in USA it is 8 Mg ha−1, which is, indeed, a phenomenal figure. It is in the above context that one has to clearly understand the importance of “The Nutrient Buffer Power Concept”. The following instance of Cardamom yield from the State of Kerala, gives a definite answer to this question. These details are given in the following table (Table 2.4). To understand better the above details, data in the following table (Table  2.5) would describe the K buffer power details. The details in the below table (Table 2.5), clearly show that the routinely used NH4 OAc extraction to determine the “available’ Potassium is a totally unreliable soil test.

Table 2.4  The remarkable influence of the nutrient “Buffer power” on cardamom Indian region/state

Crop yield (kg ha−1)

Indukki (Kerala State) Coorg (Karnataka State)

80 155

Regression Function (Y= a+bx) 592.46 + 0.917x 142.38 + 1.44x

Note: In the regression function Y = a+bx, the “b” value represents the K buffer power, while the “a” value is a constant, the intercept in the linear function. Note that the Coorg soils have 57.03% more K buffer power compared to the Idukki soils. And, now look at the Cardamom yields. The Coorg soils have yielded 193.75% more Cardamom compared to the Idukki soils. The K buffer power refers to pooled values on K analysis from 94 locations covering more than 24,000 hectares spread over the two States, Kerala and Karnataka, in India. Source: Nair, K.P.P. 2016. The Nutrient Buffer Power Concept For Sustainable Agriculture. Notion press, Chennai, India Table 2.5  The inter-relationship between cardamom leaf potassium content and the routine soil test for potassium Details

Regression function

Region

Leaf Potassium vs. Exchangeable Potassium Leaf Potassium vs. Exchangeable Potassium

Y = a + bx Y = 1.645 + 0.000006 Y = 1.270 + 0.0004

Idukki Coorg

Correlation Coefficient “r” value −0.006 0.206

Important note: The routinely employed soil test for available Potassium (NH4) OAc has given either a very low correlation coefficient (“r” value) or a negative correlation coefficient with the leaf content of Potassium, clearly demonstrating that this is a totally unreliable soil test.

2.8  How Do We Advance Food Security?

21

2.7 What are the Practical Consequences of This Finding for the Cardamom Farmer? The Cardamom plant is a very heavy feeder of Potassium. For an irrigated cardamom crop 250 kg/ha of Potassium is recommended while for a rainfed crop only 150  kg/ha is recommended. Normally, the quantity is twice that of nitrogen and phosphorus. At INR 80 (about US $ = 1.25 at current rate of international exchange) for a kg of Potassium, in India, the above recommendation works out to be a big sum, more than for Zinc, discussed earlier, in this book, for the Cardamom farmer. And, if a Cardamom farmer goes by this advice based routine soil test for Potassium (NH4) OAC as discussed above, the famer will end up spending a lot money wastefully. But, if he goes by the “The Nutrient Buffer Power Concept”, he would save a lot of money on Potassium fertilizer (either Muriate of Potash (KCl) or sulfate of Potash (K2 SO4).

2.8 How Do We Advance Food Security? During the biblical era the world population was just around 0.2 billion. In the next millennium it increased by just 0.31 billion, by 1000 AD. However, the global population increased twenty – fold in the next millennium to 6 billion by 2000 AD. By 2050, the world population is projected increase to 9.4 billion, which is an crease of 157%. This would be, without any doubt, an exponential increase in food demand. Where shall we go for the extra food to feed the extra mouths? That seems to be the crucial question. The most remarkable and very striking aspect of the future escalation of population dynamics is that almost all of the projected increase in population, which is about 3.5 billion, will take place in the developing countries of Asia (mostly in South Asia, India, Pakistan and Bangladesh, in particular) and Africa (mostly in Sub-Saharan Africa, namely in countries, such as, Angola, Benin, Botswana, Burkina Faso, Burundi, Cabo Verde, The Republic of Cameroon and the Central African Republic). It is very important to point out in this context, that, if one takes the case of South Asia, especially countries, such as, India, Pakistan and Bangladesh, it is in these countries that most of the soils are now heavily degraded, thanks to the “green revolution”. India, is, indeed, the most illustrious example, where, the State of Punjab, is known as the “cradle of Indian green revolution”. Of the 328.73 million hectares of India’s geographical area, more than 120.40 million hectares have now degraded soils, and almost all these soils are in States like Punjab, Western Uttar Pradesh, Andhra Pradesh and Tamil Nadu, where the green revolution was heavily practiced. It is very important to note that the soil degradation in these States took place during the green revolution phase.

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2.8.1 The Focus of This Book Judicious management of the soil resources, plant nutrients and water is an important strategy to adopt to meet the challenges posed by global climate change. It is noteworthy to observe that as much as 35% contribution to global warming is contributed by the green revolution (Nair 2019). The focus of this book, would, however, be on a revolutionary soil management technique, now globally known as “The Nutrient Buffer Power Concept. The concept, when practiced in practical situations, would also counter/mitigate the ill effects (environmental hazards) of climate change. Plant nutrient depletion and imbalance in soil, is unquestionably, the most critical factor in optimizing crop yield. The following table (Table  2.6) gives a summary of global nutrient depletion. Data in the above table, are, indeed, very alarming. And, most interestingly, of the highest area covered in the data collection, it is Potassium that tops the list. Equally important is the case with Phosphorus. Though the percentage of depletion in the case of nitrogen is fairly large, it comes under a different category. This is because, within the ambit of “The Nutrient Buffer Power Concept”, where the dynamics of nutrient bio availability of three most important plant nutrients, namely, Phosphorus, Potassium and Zinc, has been intensely investigated across three continents, namely, Europe, Africa and Asia, there is link between these three, namely, the mode of their bio availability, which is diffusion in soil, which be discussed below. Nitrogen does not come under this category, as its bio availability is mainly governed by mass flow and root interception. Soil nutrient depletion is primarily attributed to a lack of or inadequate use of fertilizers, imbalanced fertilization, and, losses caused by erosion, leaching, volatilization and consumption by weeds. Of these, imbalanced fertilization is the most serious issue. It is important to remember here that crop yields in developing countries are strongly related to the inputs, especially of synthetic fertilizers. The foregoing discussion in this book has shown the magnitude of nutrient depletion, primarily of nitrogen, phosphorus and potassium. These three nutrients, are the principal and deciding nutrients of a crop’s performance in the field. Additionally, of late, Zinc is showing a clear-cut of deficiency in many tropical soils, especially those, where the “green revolution” has been practiced over some decades. India is a typical example. This is because, in highly soil-extractive farming, which is highly chemical-­ centric, as in the case of the green revolution, at the beginning, native Zinc is extracted by plant roots, and, due to the heavy extraction of nutrients, it takes a Table 2.6  Summary of global nutrient depletion Nutrient Nitrogen Phosphorus Potassium

Percentage of harvested area 59% 85% 90%

Source: Tan et al. 2005. The data is calculated up to 2000 AD

Percentage of depletion 18.7 kg ha−1 year−1 5.1 kg ha−1 year−1 38.8 kg−1 year-1

2.9  “The Nutrient Buffer Power Concept” in Brief

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while before deficiency is thrown up. Acute Zinc deficiency started to manifest in the soils of Punjab State, the “cradle of Indian green revolution” in India, beginning mid seventies only. The green revolution was put in place in mid sixties, and, it took nearly a decade to throw up Zinc deficiency. It started with Punjab State, and, gradually, spread to other neighbouring States, where the green revolution had taken hold of, starting mid sixties. My research on “The Nutrient Buffer Power Concept” has concentrated on Phosphorus and Potassium, among the major plant nutrients, and Zinc among the micro nutrients. Nitrogen was excluded. The reason for this approach was because there is a great difference in the pattern of bioavailability and plant root uptake of these four nutrients. While nitrogen follows the path of “mass flow” and “root interception”, Phosphorus, Potassium and Zinc follow the principle of diffusion in their bioavailability, uptake process. Hence, it was important to understand the true thermodynamics of these three nutrients. The basic concepts are discussed, elaborately, elsewhere (Nair 1996). However, a brief mention and description of the processes involved in the dissolution of important nutrient ion from the soil matrix and of plant root uptake is in order, as described below. All of the above detailed discussion, brings us, naturally, to the central question, what is the Buffer Power Concept. The following discussion pertains to this question, rather briefly, though for more details, I suggest the reader refer my first chapter on the theme in Advances in Agronomy (Nair 1996).

2.9 “The Nutrient Buffer Power Concept” in Brief 2.9.1 Basic Concept I would start from the basic premise that one of the greatest follies that can lead to many scientifically wrong assumptions which has been committed by soil scientists and agronomists, the world over, is their implicit assumption that a few milligrams of a field soil extracted with a specific chemical extractant in the laboratory, using a specific extraction time, an extraction ambience like revolutions per minute used, represents the accurate “bio available” fraction of this nutrient ion to the plant root in the entire field soil. This would never be the case, as my field experience, over three decades, in Europe, Africa and Asia, has very clearly shown. In the first place, the manner in which a soil sample is collected from the field, is the starting point from where serious scientific errors can start to creep in, once this soil sample is not scientifically collected. For instance, a field will have fertility gradients and unless this is taken into account, a few grams of soil sample taken from a corner of the field or the middle of the field can never be truly representative of the entire field. This is important to remember because in an extraction, what we are aiming at is to characterize the fertility/nutrient status of the entire field. I have developed a method of taking, as much as a truly representative soil sample, by taking paces, criss-cross,

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2  Soils and Food Sufficiency

along the entire field, taking a few grams of soil sample from each spot, mixing all of the samples up, and taking a few grams/milligrams, as the case/need be, for extraction, or even when employing the adsorption-desorption equilibrium method that I have developed (Nair 1992). This procedure will take care of the differences arising out of fertility gradients. In the final analysis, it is the plant and plant alone that will decide whether a nutrient and/or a fraction of it in the soil is “bio available”. Hence, for a sound understanding of the bio availability of a specific plant nutrient in the soil, one must address the central question of the thermodynamics involved between the plant root surface and the soil particle. Mengel (1985) has hypothesized that there is very close, almost linear, relationship in a low concentration range of