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Calling For a Brown Revolution and Regreening to Restore Soils

by Peter Gubbels, Director of Action Learning and Advocacy, West Africa

When meeting with an assembly of rural villagers in the Kaffrine region of Senegal 3 years ago, I inquired about the main problems they faced in their agriculture. One older woman, attired in a colorful West Africa cloth, but with a weathered face and gnarled calloused hands, rose. She declared, eloquently, with utter conviction in front of the elders, “our main problem is that our soil is dead.”

This woman farmer was speaking about her village, where she had lived all her life. But her experience and her assessment of the problem has been echoed by millions of small scale farmers in villages across the Sahel and West Africa. Soil degradation is a major, growing, but largely quiet crisis in the region which is having, together with climate change, major impacts on food and nutrition security and livelihoods.

West Africans have farmed their land for centuries. Why has soil degradation, and the hunger and malnutrition it engenders, evolving into a massive crisis?

There are many reasons, but at the root of the problem is the loss of healthy soil. For countless generations, and across the rise and fall of many West African empires, smallholder farmers were in a sustainable equilibrium with nature. When population densities were low, and the land was abundant, farmers maintained soil fertility by fallowing. This entailed letting a field “rest” for 10 or more years, letting the trees, grass cover and natural vegetation re-grow to cover and protect the soil.

The trees in particular protected the soil against the wind. The trees’ roots pulled up nutrients from deep within the subsoil and restored it to top of the soil in the form of a leafy mulch and organic matter. Through fallowing, farmers used the ecological processes of nature (and time) to replenish soil health.

Today, much of the land in the Sahel has lost much of its vegetative and tree cover. Increased population levels mean there is much less land. Fallowing is often no longer possible. In response, governments, influenced by Western industrial agriculture, have promoted chemical fertilizers, herbicides, pesticides. These agrochemicals, coupled with the introduction of monoculture of a limited number of commercial, hybrid seeds, have undermined the soil health, and killed its rich micro-organisms, and depleted levels of organic matter which is key for making nutrients available to plants.

The quiet crisis of soil degradation is not limited to West Africa and the Sahel. In different manifestations, it has become a global problem. It is fast becoming one the most daunting of this century’s challenges, in particular, because it is so intimately linked to climate change.

The problems of soil degradation and erosion have plagued humanity since the dawn of agriculture. Although it is most of our making, and well within our power to solve, our modern farming and food systems do not take it as seriously as other social and economic problems.

By far, agricultural research invests most heavily in improved plant genetics, agrochemicals, and biocides.

Soil is our most underappreciated, least valued, least considered but yet essential natural resource. This has to change. We have to shift our thinking of soils from a mere substrate for growing plants to ecological systems, including myriads of microorganisms for feeding plants, and trees, and thereby ourselves.

One handful of healthy soil contains more micro-organisms than there are people living on earth. The thin layer of topsoil, that we walk on and through which plants send their roots, is as important as the thin layer of the earths’ atmosphere. It is the result of enduring, age-old processes of decomposition, transformation, and accretion through countless organisms. Most of these organisms are microscopic and at present, we only know a fraction of them.

Healthy soil is the foundation of agriculture and a vital part of ecosystems and earth system functions that support the delivery of primary ecosystem service. Most importantly, given the climate change crisis, soils have a key role to play for storing carbon.

Soils store more than 4,000 billion ton of carbon. By way of comparison, the forests store 360 billion tons of carbon as woody biomass, and the atmosphere more than 800 billion ton in the form of carbon dioxide.

Yet, across the globe, including the United States (not just in Senegal, or the Sahel), we are running down our stock of fertile top soil. The estimated rate of world soil erosion exceeds new soil production by as much as 25 billion tons a year, an annual loss of about 1% of worlds’ total stock. United Nations (UN) reports that on a global scale, around 10 – 20% of drylands and 24% of the world’s productive lands are degraded. Every year, soil erosion and other forms of land degradation rob the world of 5-7 million hectares of farming land.

Currently, the cost of land degradation reaches about US$490 billion per year, much higher than the budget for action to prevent it. Land degradation directly impacts the health and livelihoods of an estimated 1.5 billion people.

But what can we do to start rebuilding and restoring our agricultural soils? There is already much knowledge from research and practical field experience that is focused on working with soil ecosystems rather than working against them, through conventional erosive farming practices.

In the US, this involves increasing support for the development of perennial crops, low input, no-till farming, promoting practices that increase soil organic matter to both sequester carbon, and improve soil fertility.

All these practices fall under a different, alternative way of farming “with nature” rather than against nature, called agroecology.

Agroecology treats soil as an ecosystem rather than trying to make soil adapt to our technology, including plowing, and then having to compensate with chemical fertilizers and biocides, because we have mined the soil until it has become sterile dirt. Poisoning the foundation of our food web through addition to pesticides, herbicides, and chemical fertilizers is not a sustainable strategy for our global food system. The “green revolution depends on hybrid and GMO seeds developed to grow in these conditions.

What Agroecology calls for is first and foremost an alternative “brown revolution” that restores healthy soil as the foundation for all agriculture. Secondly, agroecology calls for “regreening”, using trees, cover crops, green manures, rotations with legumes, perennial crops, and minimum tillage, permanent soil cover with mulch.

This is not a return to pre-industrial practices. We do not have to choose between sustainable land use, and “feeding the world”. There is much evidence to show that agroecology (or regenerative agriculture) can match output of conventional agriculture. Not only that, restoring soil health and fertility and regreening will become increasingly vital in a post fossil fuel world, to store more carbon in soil, and increasing the ability of trees and plants on farm land to absorb carbon from the air, to mitigate climate change.

The current high erosion rates throughout the world are also of great concern because of the slow rate of topsoil renewal; it takes approximately 500 years for 2.5 cm layer of fertile topsoil to form under natural conditions. However, with effective management and “regenerative agriculture” this process of soil restoration can be greatly accelerated.

The overarching imperative, not just for the women farmers of Kaffrine, or small scale farmers across the Sahel, but globally, is to work together for a “brown revolution” and regreening.

Article was written by Peter Gubbels

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