As skin is to the animal or human body, soil is to the Earth. Usually dismissed as “dirt” or “mud”, soil is a specific scientific term and is often described by soil scientists as the Earth’s living skin: thin and delicate but also playing an irreplaceable role in preserving the health of human beings and the global biosphere as a whole.
According to Professor Bridget Emmett of the UK Centre for Ecology and Hydrology: “Soil is one of the most underrated and little understood wonders on our fragile planet.
Soil is connected to almost everything that humans do, including the plants we grow and nearly all the food we eat. That is why it requires to be preserved and restored.
“Finding a remedy will require changes that extend far beyond the soil itself,” says John Scott. “It will involve changing the way we farm and potentially the whole nature of the agrochemical industry. It could also change the way we feed people all around the world.”
Soil is a vital source of food and medicine, home to a vast reservoir of biodiversity and an important store of carbon. Soil is one of the Earth’s most valuable natural resources, yet 30 percent of our soils are degraded. Soil is one of the most ubiquitous and under-appreciated substances on Earth.
Despite being everywhere around us – in fields and gardens, and beneath our very feet as we walk the concrete and tarmac of city streets – soil is often taken for granted. Yet in several fascinating ways this miraculous substance holds the key to life on Earth.
It helps produce our food, filters and purifies our water, reduces flooding, regulates the atmosphere, and plays a crucial role in driving the carbon and nitrogen cycles. It is also one of the most biodiverse habitats on Earth.
Most of us are already aware of the importance of forests and trees in reducing the amount of harmful CO2 in the atmosphere; but few realize that soil arguably plays an even more vital role.
Plants extract carbon dioxide from the atmosphere in a process called photosynthesis, and some of this carbon is then stored or “captured” in the soil as fresh plant residues and highly decomposed material known as humus. Soil stores an extraordinary quantity of carbon: three times the amount in the atmosphere and twice the amount contained in all plants and trees.
These organic compounds are highly enriched in carbon and are known as soil organic matter (SOM) that locks carbon underground in a stable, environmentally friendly way.
However, when soil becomes damaged or degraded, it can release harmful carbon dioxide or methane back into the atmosphere, thereby accelerating – rather than decelerating – the impact of climate change.
As John Scott, Zurich’s Head of Sustainability Risk, says: “This is why the way in which we use land for agriculture is so important. By switching from intensive farming methods to organic ones, for example, we could dramatically change the emissions profile of the land. If managed in the right way, soils will be healthier and more fertile – and also store more carbon.”
Several studies of fruits, vegetables and grains have suggested a decline in nutritional value over time, but the reasons may not be as simple as soil depletion. There is considerable evidence that such problems may be related to changes in cultivated varieties, with some high-yielding plants being less nutritious than historical varieties.
Several other issues are involved, like changes in farming methods, including the extensive use of chemical fertilisers, as well as food processing and preparation. A 2004 study evaluated Department of Agriculture data for 43 garden crops from 1950 to 1999.
The researchers found statistically reliable declines for six nutrients - protein, calcium, potassium, iron and vitamins B2 and C - but no change for seven others.
Soil is essential for Biodiversity, which in turn, is essential for food security, both above and below the ground. Soil is one of the main global reservoirs of biodiversity to the extent that 25 percent of animal species on Earth live underground, while 40 percent of organisms in the terrestrial ecosystems are associated with soil at some point during their lifecycles.
“There is a vast reservoir of biodiversity living in soil that is out of sight and generally out of mind,” says the University of Manchester Professor Richard Bardgett, the lead author of a report on soils by UN’s Food and Agriculture Organization (FAO); “But few things matter more to humans because we rely on soil to produce food.”
Healthy soils provide habitats that support thousands of different species of fungi, bacteria and invertebrates, which then work in combination to drive the Earth’s carbon, nitrogen and water cycles, thereby creating the nutrients and food we need to survive.
Simply put, soil produces a staggering 95 percent of entire humanity’s food supply, by growing both the crops we eat and the grasses and other plants that are fed to the livestock.
Many life-saving drugs and vaccines from the last hundred years were discovered in the chemically rich and biologically diverse environments found in soil. These medicines range from well-known antibiotics such as penicillin, to bleomycin which is used to treat cancer and amphotericin that combats fungal infections.
Soil biodiversity also has an important medicinal role to play thanks to its relationship with plant roots. Healthy soils enable plants to produce helpful chemicals such as antioxidants which protect them from pests and other external threats.
When humans eat these plants, the antioxidants they contain boost our own immune systems and hormone regulation. It is no exaggeration to say that there is a direct connection between healthy soils and healthy humans.
When we are fully aware of the different ways in which soils helps to support life on Earth, it is doubly alarming to discover how damaged and vulnerable they have become. The FAO estimates that 30 percent of the world’s soils are now degraded. While a recent report by the European Commission estimates that between 60 and 70 percent of its soils are unhealthy.
There are multiple human-made threats to soil health. These include deforestation, urbanisation, agricultural intensification, soil compaction, acidification, salinisation, pollution, landslides, wildfires and soil erosion.
According to the FAO, soil erosion poses a major threat to global food security and could compromise the wellbeing of at least 3.2 billion people globally. What makes the situation worse and even more serious is the fact that high-quality, fertile soils cannot be quickly or easily replaced.
It takes about a century to build just half a centimetre of healthy soil, which means we are currently losing soil 50 to 100 times faster than it is able to rebuild.
The largest threat to healthy soils is agriculture. Since the Industrial Revolution an estimated 135 billion tonnes of soil has been lost from the farmland, through a combination of practices including deforestation to create more arable land, mono-cropping (growing a single crop year after year), overgrazing, tillage, the use of heavy machinery and the misuse of fertilisers and pesticides.
An important first step to minimize soil degradation is for countries to switch to “regenerative agriculture” practices. These include regular crop rotation, sustainable grazing and mixed-use farming methods such as agroforestry, which involves planting trees alongside crops.
By changing the myriad ways we farm, healthy soils can be protected from further damage while degraded soils can be restored by growing a diverse range of plants. Individuals can also play a role through the products we choose to buy and the food we choose to eat.
The most striking example of how our lifestyle choices affect the soil is the fact that although more than 80 percent of the World’s farmland is used to raise livestock, whose meat provides only 18 percent of all the calories consumed.
As Professor Nico Eisenhauer of Leipzig University, another co-author of the FAO’s soils report, observes: “A lot depends on what we eat. Do we need to eat these massive amounts of cheap meat, for example? Can we rely more on plant-derived calories? I think this is a massive factor.”
Raising awareness - both of the importance of soil and how it is currently at risk - is crucial in bringing soil health into the wider environmental debate. Until now, many of us have underestimated the richness and vitality of this unseen subterranean world.
Yet, according to Ellen Fay, the co-founder of the Sustainable Soils Alliance, its importance is hard to overstate: “Soil is crucial to the health of everything else. We can’t deliver on any of our environmental targets if we don’t deliver for soil – and we’re still a long way from doing that.”
With policymakers from across the globe brainstorming on how to restore degraded land at a UN conference, India’s spiritual leader and founder of Isha Foundation, Sadhguru, suggested a three-pronged strategy to save soil and appealed to the representatives from 196 nations to redouble governmental policy efforts aimed at reversing the degradation of agricultural land all around the world.
Addressing the 15th session (CO) of the United Nations Convention to Combat Desertification (UNCCD) conference at Abidjan, Cote d’Ivoire, Sadhguru said, “Time is running out. But fortunately, we know what to do. With the development of appropriate government policies, we can turn the clock back on the impending extinction of soil.”
Bhushan Lal Razdan, formerly of the Indian Revenue Service, retired as Director General of Income Tax (Investigation), Chandigarh.
Disclaimer: The views and opinions expressed in this article are the personal opinions of the author.
The facts, analysis, assumptions and perspective appearing in the article do not reflect the views of GK.