More than three decades ago, in a very important international scientific conference on global soil management in Hamburg, Germany, to which I was invited as a key speaker in the opening session, I referred to soil as “soul of infinite life”, which elicited an amused laughter from the audience. During the coffee recess, those amused surrounded me to ask why I referred to soil as “soul”, while the common refrain then, as of now, is that it is an inert and lifeless matter.
I wish not to dilate on the scientific hypothesis here to substantiate my statement, suffice to say, that contrary to what many think, soil has a soul, not in the sense that human body has, but, if one explores the depth of what a soil does in its minutest fraction, that is clay (less than 2 Angstrom in width, an Angstrom is one-thousandth of a millimetre) one will appreciate what I said. Let me explain a common phenomenon. We all know how important water is to life. Yet, how many of us stop to think that without soil there simply will be no water for sustenance of life on this planet? My explanation about soil becomes increasingly relevant in the context of global warming, about which there is currently much talk, because of the UN supported Inter-Governmental Panel on Climate Change report, which will be out by September-end.
In India policy makers spend colossal sums of money on water “conservation”, water “management” and so on. Yet, rarely do I come across projects which talk of “soil And water” management in one frame. Either it is soil or it is water. Without soil there simply is no water. Look at this basic electro-chemical reaction. Of all the soil particles, the clay is the most dynamic and, in my opinion, the most lively (almost akin to a soul). It has excess negative electrical charge at its surface. A water molecule (H2O) has a hydrogen (positively charged atom) bonded to oxygen (a negatively charged atom), and when rainwater falls from the sky after condensation from water vapour, this hydrogen atom is electrically attracted to the clay surface, which has a negative charge, which in turn is bonded to an oxygen atom, with negative charge, and thus a chain of water molecules is built around the clay particle. If there was no soil all the water will simply seep into the sea. And, to be sure, water simply cannot exist in outer space, except in the vapour form.
The crucial question is, what has all this to do with climate change? Let me explain. Why is it that in the Arabian desert, after nightfall, whether it is summer or winter, the atmosphere cools? And in the Terai region, at the foothills of the Himalayas, in UP, with very fertile and productive dark clay soil, it is warm even after nightfall? The answer is, in the Arabian desert, the white sand reflects all the heat absorbed during day, while in Terai, the black clayey soil absorbs all the heat and simply cannot reflect it at night.
Let me now link it with the global climate change, and how, one can bring about mitigation through intelligent soil management. The common refrain among environmentalists is that all that happens above the earth’s surface (or what many mistakenly confuse with the so-called environment) only is important. Not many understand the crucial role soil plays in climate change. The centrality of soil is, more often than not, overlooked. This has been the bane of the chemically-powered Indian agriculture, euphemistically called the “green revolution”. Global climate, the past decade and a half, has not been warming up at rates earlier predicted. In fact, the rate of warming over the past decade and a half from 1998-2012 at 0.05 degree Celsius per decade, is comparably less than that during the six decades between 1951-2012 —0.12 degree Celsius per decade. In absolute terms, between 1951 and 2012, that is six decades, the increase was 140 per cent, that is nearly 24 per cent per decade, which is a substantial increase given the global scale. This simply shows that the rate of increase of late is much lower than what pessimists try to make out. This in no way is room for solace. We have many other contributory factors that are quite worrying.
Of all human activities, high-input chemical agriculture contributes substantially to global warming, which many are unaware of. Most environmentalists pin down carbon dioxide as the biggest culprit in global warming. But we have one factor, N2O (nitrous oxide), a by-product of chemical changes from nitrogenous fertiliser application in soil, a far bigger culprit than carbon dioxide, contributing to global warming. N2O naturally occurs in atmosphere as part of the earth’s cycle, and has a variety of natural sources, chemically-driven agriculture being the main one. N2O molecules stay in the atmosphere for an average of 120 years before being removed or destroyed through chemical reactions. A pound of N2O causes over 300 times more to global warming than a pound of carbon dioxide, emanating from industrial activities or automobile emission. In a highly industrialised US agriculture, N2O emissions from soils have increased 80 per cent between 1990 and 2011, accounting for about 5 per cent of all greenhouse gases combined contributing to global warming. Agricultural soil management is the largest source of N2O emissions in US, accounting for 69 per cent of total emissions in 2011.
What important lesson should India take against the backdrop of the above phenomenon, totally underplayed by the so-called environmentalists?
India must completely reorient its soil management techniques to make its agriculture sustainable in the long run and, also, in the process, dramatically lessen India’s contribution of its own share of global warming, which will first affect us and then only others. Go to Punjab, the “cradle” of the chemically-powered green revolution to understand what I say here. The soils are degraded, the aquifers dried, groundwater polluted rendering it non-potable because of excessive nitrate loading (emanating from unbridled urea use) and biodiversity vanished due to continuous rice-wheat monoculture. No balance sheet of N2O has been made here. And none knows how much of warming has been contributed by this mindless farming, which while producing extra food, ruined India’s soils and environment. A revolutionary soil management technique, developed by the author, during more than three decades of research in Europe, Africa and Asia, now globally known as The Nutrient Buffer Power Concept, might hold some important answers.
The author is an international agricultural scientist and can be reached at drkppnair@gmail.com