Soil — the substance you walk on, build on, and live from — provides your food, clothing, and even the air you breathe. It gives warmth, shelter, and the goods you possess. Soil is, I believe, a substance that is under-acknowledged, and also under attack, and its misuse is contributing greatly to the excessive release of CO2 into our atmosphere – making it a large contributor to global warming. Therefore, I felt it high time we came to its defense. Here goes.
Firstly, what is soil? Unfortunately, and increasingly, the modern mindset simply regards it as ‘dirt’ – something to clean off your nine-year old son’s knees if he’s fallen out of that tree, or worse, at an industry level, its regarded as nothing more than an inert medium for sowing plants – just somewhere to put them. For agri-businessmen, little or no connection is made between the health of the soil, and the health of the plants they produce. The mechanised treatment of the soil is arbitrary and aggressive, and the consequences of this disconnect are dire.
|More Than Just Dirt! There are over four billion micro-organisms in a teaspoon of healthy soil|
You could simplify its composition by reducing it to four main components: minerals, air, water, and organic matter. The complicated version, however, is almost beyond belief, and despite the best efforts of scientists many aspects remain mysterious.
Hidden from immediate notice, a healthy soil contains innumerable micro and macro-organisms. In fact (and I haven’t counted these personally) there are said to be over four billion micro-organisms in just one teaspoon of healthy soil. If you were to add the combined weight of all the living micro-organisms in an average acre of land, they’d weigh about as much as a typical domestic cow. These organisms work with each other, and with plants, in a symbiotic relationship that ultimately provides for the needs of all creatures that walk, fly, or swim on our planet. Part of their work is to break down decaying organic matter, along with minerals in the soil, and then make these available to plant roots in a nutrient form they can utilise. They are essentially an immense army of recyclers – working for our benefit without reward and with scant recognition.
This natural process of micro-organisms feeding plants is significant, and highly complex. Through the work of these creatures a plant receives what we might call a ‘balanced diet’. To illustrate: What do you think a small boy would do if you gave him an enormous bar of chocolate to eat? Chances are good he’d keep eating it until it made him sick (even if half of it is still left on his face!). Children are unable to gauge an appropriate quantity, and will quickly scoff all they can fit in. The result? Even if he doesn’t make himself ill, your child goes on a physical and emotional roller-coaster ride until the refined sugar-induced energy dissipates. A wise parent might instead supply an appropriately sized portion of ’sugar’ in its natural state – bound up with fibrous dry matter in the form of whole fruit.
Modern agri-businesses do similar with their water-soluble fertilisers – they set a ‘meal’ before the plant that can be immediately absorbed by plant roots, essentially by-passing the balanced slow-release feeding by micro-organisms. Just like a child, this affects a plant’s health.
Pesticide residues are not the only problem arising from modern agricultural techniques. Increasingly, nitrate levels in vegetables are causing concern, although most attention so far has been focused on nitrates in water supplies…. About 70% of average daily nitrate intake comes from vegetables, compared with only 20% from drinking water. Nitrates are taken up very readily by crops, and if they are not utilised immediately in the formation of protein, they are stored in the cells in their original form. There is then the risk that when nitrates are ingested or cooked, they convert to nitrites which can potentially combine with amines to form carcinogenic nitrosamines. – Organic Farming, Nicholas Lampkin p.565.
Additionally, in the insect and plant world the weak are attacked first, just like lions and antelope on the savanna! Plants grown in a healthy soil using sustainable methods are consistently shown to be resistant to attack from insects and diseases.
Our newsletters have often explained how mycorrhizal fungi attach to plant roots and bring great amounts of needed nutrients to the plant, functioning like millions of extra feeder roots. These well-nourished plants become more disease resistant and produce higher yields or more flowers.
A less obvious benefit is reduced insect attacks. In our grow testing, we can often tell the mycorrhizal plants from control plants from some distance away, not just by size but also by a difference in leaf damage.
This same sort of difference can be seen by comparing plants fertilized with slow-release fertilizer versus those given fast-acting forms, especially liquids. The quick greening and rapid burst of growth that you get after drenching plants with liquid fertilizer is obviously an invitation to harmful bugs.
So what’s going on? There are different theories about this subject, but one is that certain insects are programmed by nature to eliminate sick or otherwise imperfect plants. When you create unnaturally lush growth on a plant, something about those leaves seems to be like a neon sign that triggers the “must destroy” instinct in bugs, even though the plant may look normal to our eyes.
Another theory is that completely healthy plants produce a substance that tastes bitter to insects – sort of a natural repellant – but a plant that is pushed with fast NPK fertilizer apparently does not form those anti-bug substances and tastes delicious.
Whatever the reason, the way to grow plants that won’t require drenchings of toxic rescue chemicals is to use small amounts of slow-release nutrients that are delivered as-needed to the roots by biological action. The use of any high-analysis fertilizer, especially in liquid form, seems to be a major cause of insect attacks.
Of course, the nice companies that so heavily promote their wonder fertilizers are also happy to sell you bug sprays later. But I’m sure they don’t realize that their plant food is creating the need for insect protection. Real sure. – BioOrganics
The soil, if allowed, will absorb more CO2 than it gives out
Another significant, and highly relevant, role of soil micro-organisms, is carbon sequestration (storage):
The estimated amount of carbon stored in world soils is about 1,100 to 1,600 petagrams (one petagram is one billion metric tons), more than twice the carbon in living vegetation (560 petagrams) or in the atmosphere (750 petagrams). Hence, even relatively small changes in soil carbon storage per unit area could have a significant impact on the global carbon balance.
Carbon sequestration in soils occurs through plant production. Plants convert carbon dioxide into tissue through photosynthesis. After the plants die, plant material is decomposed, primarily by soil microorganisms, and much of the carbon in the plant material is eventually released through respiration back to the atmosphere as carbon dioxide.
But some of it remains when organic materials decay and leave behind organic residues, often called humus. These residues can persist in soils for hundreds or even thousands of years. – Geotimes
Given all the attention and commotion over global warming today, this ability of our soil to naturally assimilate CO2 on a grand scale should be examined far more than it is. This ‘humus’, mentioned above, is the dark black content of a healthy soil – black due to the carbon content itself. Humus could best be described as the final result of decaying organic matter. It is a stable substance – slow to accumulate, and slow to deplete – and is critical for the soil’s biological activity. This stable state is in stark contrast to our industrial fertilisers, which, in addition to over-absorption by plants, also contaminate streams and rivers and leach into our water table.
Subsequent decomposition of dead material and modified organic matter results in the formation of more complex organic matter, called humus. This process is called humification. Humus consists of a group of humic substances that includes humic acids, fulvic acids, hymatomelanic acids and humins and is probably the most widely distributed organic carbon-containing material in terrestrial and aquatic environments….
Humic substances enhance plant growth directly through physiological and nutritional effects. Thus humic acid is capable of improving seed germination, root initiation and uptake of plant nutrients, and serves as a source of nitrogen, phosphorus and sulphur. Indirectly, they may affect plant growth through modifications of physical, chemical and biological properties of the soil, such as an increase in water holding capacity and cation exchange capacity, and improvement of tilth and aeration through good soil structure. – FAO
Humus is a rich resource – and could easily be compared to a modern day bank. Deposits and subtractions are made by the natural rhythm of decay and recycling through the weathering of air, water, and complicated interactions of various types of soil macro and micro-organisms. This ‘bank’ has been our central ‘financial institution’, sustaining our race for millennia, although there have been times in our history, in localised areas, where subtractions have exceeded deposits – resulting in biological bankruptcy.
Throughout history, the story has repeated itself: Great civilizations have grown where soils were fertile enough to support high-density human communities, and fallen when soils could no longer sustain our rough treatment. According to the International Task Force on Land Degradation, the great early civilizations of Mesopotamia arose because of the richness of their soils, and collapsed because of declines in soil quality. Poor land management and excessive irrigation caused soils to become increasingly degraded, leading to power struggles, migrations, and ultimately, the collapse of the Fertile Crescent civilizations.
Ancient Greece suffered a similar fate. The philosopher Plato, writing around 360 B.C., attributed the demise of Greek power to land degradation: “[In earlier days] Attica yielded far more abundant produce. In comparison of what then was, there are remaining only the bones of the wasted body; all the richer and softer parts of the soil having fallen away, and the mere skeleton of the land being left.”
Many experts also blame the collapse of the great Mayan civilization and the peaceful Harappan society of the Indus valley on soil exhaustion and erosion, resulting from agricultural practices and clear-cutting of forests. According to Jared Diamond, a UCLA professor and author of the books Guns, Germs and Steel and Collapse, 90 percent of the people inhabiting Easter Island in the Pacific died because of deforestation, erosion and soil depletion. In Iceland, farming and human activities caused about 50 percent of the soil to end up in the sea, explains Diamond. “Icelandic society survived only through a drastically lower standard of living,” he says. – The Scoop on Dirt, Tamsyn Jones
Since the use of the plough, then the tractor, and especially since WWII military chemical companies found a post-war use for their chemicals (pesticides, then fertilisers), the organic content of our soils, and consequently soil and plant health, has been in serious decline. This has resulted in even more fertilisers being applied to boost productivity, and the resulting poor health of plants subsequently encouraging the use of even more pesticides.
Costly petroleum-based fertilisers have long been touted as the solution to the world’s problems of poverty and hunger by the industries that produce them, but their use has not only necessitated pesticide application, but also encouraged a complete disregard of the free, and healthful, systems of fertilisation that are already available to us. This food-in-a-test-tube mentality is forgetting a significant fact – even putting plant health and water purity aside, this kind of agribusiness is wholly finite. As a soil’s inherent fertility is squandered the soil loses its structure. These lifeless soils become increasingly difficult to use, even as an ‘inert medium for placing plants’. The term ‘increasingly difficult’ translating to more expensive and energy intensive (i.e. increased mechanised interventions). Ultimately these lifeless soils are discarded and become what we call ‘marginal lands’ or ’set-asides’, forcing increased output on that which remains – or increased deforestation, so we can gorge ourselves on fresh virgin soil.
To our shame, the rich black soils that were commonplace in America when the Mayflower landed, the natural accumulation of centuries of natural processes, are now largely a thing of the past. Besides issues of plant and human health, water contamination and loss, soil compaction, erosion and desertification – this has also meant the carbon absorption ability of the soil has decreased significantly. Great quantities of CO2 that should be stored in the humus content of healthy soils have been systematically released into the atmosphere.
|Much of the world is suffering from degraded soil fertility|
- During the past 40 years nearly one-third of the world’s cropland (1.5 billion hectares) has been abandoned because of soil erosion and degradation.
- About 2 million hectares of rainfed and irrigated agricultural lands are lost to production every year due to severe land degradation, among other factors.
- It takes approximately 500 years to replace 25 millimeters (1 inch) of topsoil lost to erosion. The minimal soil depth for agricultural production is 150 millimeters. From this perspective, productive fertile soil is a nonrenewable, endangered ecosystem. – The Global Education Project
A Cornell University scientist says soil around the world is being swept and washed away 10 to 40 times faster than it’s being replenished.
Professor of Ecology David Pimentel says cropland the size of Indiana is lost each year, yet the Earth’s need for food and other grown products continues to soar.
“Soil erosion is second only to population growth as the biggest environmental problem the world faces,” said Pimentel. “Yet, the problem, which is growing ever more critical, is being ignored because who gets excited about dirt?”
Pimentel said 99.7 percent of human food comes from cropland, which is shrinking by nearly 37,000 square miles each year due to soil erosion, while more than 3.7 billion people are malnourished.
The study, which pulls together statistics on soil erosion from more than 125 sources, notes the United States is losing soil 10 times faster — and China and India are losing soil 30 to 40 times faster — than the natural replenishment rate.
Damage from soil erosion worldwide is estimated to be $400 billion per year. – Physorg.com
Thankfully, we also have historical record of peoples that have managed to not only survive on the same pieces of land, but prosper, even with highly populated, intensive agricultural production. One well-known reference book on this subject is Farmers of Forty Centuries (now available as a freely downloadable ebook ), documenting four thousand years of successful sustainable management by Chinese, Japanese and Koreans. The systems of these past agriculturally-sustainable nations have, despite their not having microscopes or beaker tubes, maintained (or indeed, improved) the soil over the course of many centuries – and despite operating an almost completely ‘closed system’, i.e. without importing fertilisers, let alone pesticides, etc., which we today use in huge amounts, and which are produced at high financial and environmental cost from finite fossil fuel sources.
We’ve ascertained that a healthy soil is one that is abundant in soil life, but how do we increase and maintain this fertility? Well, our macro and microscopic friends have just a few simple needs – needs that are actually very similar to our own.
Channels created by plant roots and the very porous texture of a humus-rich soil, provide the right amount of air for balanced microbial activity. I say ‘balanced’, because you can have too much of a good thing. Over aeration of the soil through ploughing and tilling (if it doesn’t bury the organisms to a depth where they cannot function and are destroyed entirely) can cause excess activity (or, to use a modern phrase – hyperactivity), hastening the breakdown of organic matter and humus. Using our financial analogy, it’s like blowing a month’s wages in a week. This is often followed by a complete lack of oxygen with which to work – as the reduced soil texture, combined with compaction from heavy equipment, creates anaerobic conditions that destroy soil life and encourage disease.
A healthy soil, rich in organic matter, holds, filters and purifies downwardly mobile water, and also allows the upward movement of water through capilliary action. Even sandy soils, which generally leach both water and nutrients very fast, can hold considerable amounts of moisture if it has a high organic content. Heavy soils, those high in clay, often hold too much water (especially after the compacting effects of tractors, etc.) due to very fine-grain structure and water-binding nature of clay particles. Overdosing in water essentially drowns micro-organisms, as it robs them of the oxygen they need to survive. These heavy soils also benefit greatly from a high humus content, as it again encourages the porous texture that allows for the free flow of water (and air) needed for healthy microbial action. This texture is also essential in heavy soils or plant roots cannot penetrate.
Energy comes through the presence of organic matter itself – something almost always removed (or buried out of reach of micro-organisms) in the modern ’sterile’ system of agriculture.
The question of how to restore and maintain soil fertility is best asked of nature herself. What would happen to the world if, today, we all just got up and left – if we had the means and ability to head off to a fresh new planet where we could just start all over? Now, I’m not asking you all to leave – hey, I like you guys – but what would be the result back down here on terra firma? What, in particular, would happen to our soil in that huge percentage of inhabitable land that we are currently using intensively for agricultural purposes?
Give the worms a fighting chance!
Those fields that have been ploughed and turned and churned would, with relief I dare say, surrender to the restorative influence of an amazing natural process. Firstly, in our absence, plants that are specifically able to grow in each condition (some like to call them ‘weeds’) would spring up to do what nature always seeks to do with soil – cover it up! This protective covering prevents erosion and loss from wind and rain (a good topsoil is slow in the making – so erosion is like a bank-robbery). Next, this thin initial film of ground cover would, through photosynthesis and root action, slowly, in an almost self-sacrificial manner, develop an improved state – in doing so rendering itself redundant and promoting the growth of a new phase of plants, which in turn would improve the soil further, and so on. The inevitable cycle of life, photosynthesis, root action, death, decay and recycling (including the addition of animal ‘by products’) would ultimately restore a healthy structure (tilth) and bring our exhausted soils back to verdure. It’s a hard thing to say – but we’re just plain not needed, and are usually positively damaging!
Of course, as much as we’d like to stop the earth and get off, we cannot just head off to another planet (indeed – we shouldn’t be allowed if we haven’t figured out how to look after this one). The good news is if we can imitate nature’s practices as closely as possible, and incorporate these into our farming methods, we can reverse the unsustainable pressures we’re currently placing on our land.
Working with living creatures, both plant and animal, is what makes agriculture different from any other production enterprise. Even though a product is produced, in farming the process is anything but industrial. It is biological. We are dealing with a vital, living system rather than an inert manufacturing process. The skills required to manage a biological system are similar to those of the conductor of an orchestra. The musicians are all very good at what they do individually. The role of the conductor is not to play each instrument but rather to nurture the union of the disparate parts. The conductor coordinates each musician’s effort with those of all the others and combines them in a harmonious whole.
Agriculture cannot be an industrial process any more than music can be. It must be understood differently from stamping this metal into shape or mixing these chemicals and reagents to create that compound. The major workers – the soil microorganisms, the fungi, the mineral particles, the sun, the air, the water – are all parts of a system, and it is not just the employment of any one of them but the coordination of the whole that achieves success. – Eliot Coleman, The New Organic Grower, p.3, 4.
Sustainable farming can be described as “one that meets the needs of the present without compromising the ability of future generations to meet their own needs”. Such a statement would automatically lead one to think wistfully about the needs of future generations. But, we need to realise we are the future generation. We are, today, the people that have to deal with depleted, humus-reduced (which translates to carbon-reduced), unproductive soils that have been handed down to us from decades of plundering. Over the past several decades people have made themselves rich, withdrawing from the financial institution that is our soil – and never giving back. We are facing biological bankruptcy, and, despite the good intentions of many energetic promoters of organic farmers, our world is so specialised and distanced from nature that our politicians seek to not only continue these subtractions, but substantially increase the burden already placed on our soils.
The word irresponsible is defined as “not having or showing any care for the consequences of personal actions”. Modern large-scale industrial agriculture is exactly that. We need to turn it around.
In order to understand our own time and predicament and the work that is to be done, we would do well to shift the terms and say that we are divided between exploitation and nurture….
Let me outline as briefly as I can what seem to me the characteristics of these opposite kinds of mind. I conceive a strip-miner to be a model exploiter, and as a model nurturer I take the old-fashioned idea or ideal of a farmer. The exploiter is a specialist, an expert; the nurturer is not. The standard of the exploiter is efficiency; the standard of the nurturer is care. The exploiter’s goal is money, profit; the nurturer’s goal is health – his land’s health, his own, his family’s, his community’s, his country’s. Whereas the exploiter asks of a piece of land only how much and how quickly it can be made to produce, the nurturer asks a question that is much more complex and difficult: What is its carrying capacity? (That is: How much can be taken from it without diminishing it? What can it produce dependably for an indefinite time?) The exploiter wishes to earn as much as possible by as little work as possible; the nurturer expects, certainly, to have a decent living from his work, but his characteristic wish is to work as well as possible. The competence of the exploiter is in organization; that of the nurturer is in order – a human order, that is, that accommodates itself both to other order and to mystery. The exploiter typically serves an institution or organization; the nurturer serves land, household, community, place. The exploiter thinks in terms of numbers, quantities, “hard facts”; the nurturer in terms of character, condition, quality, kind. – Wendell Berry, The Agricultural Crisis a Crisis of Culture, p. 13, 14.
Exchange our current large-scale monocultures with smaller more diverse systems that include crop rotations , green manures , leys, composting and animal wastes, and we may yet regain that which we’ve lost. The laws of nature are a powerful force. We do not have the power to alter them, even though some would try, nor can you break them without consequence. Work in harmony with nature, however, and we will get back not just our soil fertility, but also health of body and character, and our relationship with the land.
Civilisations have come and gone, disintegrating, relocating and learning hard lessons about soil-abuse. Relocating is not an option anymore. We cannot wait for the 20/20 vision of hindsight – as there are no more frontiers. Continuing on this agricultural trajectory will see wealthy countries collapse – although not before turning to plunder the soil and water reserves of weaker nations.
In the last century the global population has exploded from two billion people to over six and a half billion today. Our society must learn, or collapse. It’s as simple as that.