Healthy soils can boost food security and climate resilience for millions

Healthy soils can boost food security and climate resilience for millions

Tougou village in northern Burkina Faso has a challenging climate for farming. During the dry season, which lasts from November to May, the Harmattan blows — a dry, dusty wind coming in from the Sahara. Drought alternates with periods of flooding, sapping soil fertility and destroying crops.

Despite the climate, villagers in Tougou have recently been able to double their crops of millet and sorghum within just a year, largely thanks to a checkerboard pattern of pits filled with manure they dig across their fields. These pits, known as zaï, help concentrate precious water and nutrients at the plant’s base and attract termites, whose tunnels break up the soil, bringing it back to life.

Drylands take centre stage this week as world leaders gather in Ordos, in the Inner Mongolia region of China, for the thirteenth session of the Conference of the Parties to the UN Convention to Combat Desertification (UNCCD COP13).

When healthy, drylands like those stretching across northern Burkina Faso are covered in a rich but fragile fabric of life, most of which is hidden underground. Rain-fed agriculture in these regions depends on underground ecosystems of bacteria, fungi, termites, and other species that keep the soil fertile.

But the health of many dryland ecosystems has declined dramatically over recent decades, largely due to unsustainable farming methods, increasing drought, deforestation, and clearance of natural grasslands. Burkina Faso is hardest hit of all of Western Africa, with 40 percent of its soils severely degraded. Desertification is costing the country nine percent of national agricultural GDP annually.

The problem extends far beyond Burkina Faso. Drylands — including deserts, grasslands, and savannahs — stretch over 40 percent of the Earth’s surface and are home to a third of the global population, including some of the poorest communities in the world. Changing the way drylands are farmed to conserve life underground is the only way of restoring these ecosystems and the agricultural outputs they sustain.

From the savannahs of Africa to the Mongolian steppe, traditional farming methods such as zaï, nomadic livestock herding, and agroforestry, which involves planting trees alongside crops to maintain soil moisture, work in symbiosis with nature. Conservation agriculture is another sustainable farming method based around maintaining vegetation cover, rotating crops, and minimising soil disturbance.

Globally, sustainable farming methods are on the rise. Agroforestry and conservation agriculture are both increasing, with over eight percent of all cropland estimated to be under conservation agriculture (Friedrich et al., 2012; Jat et al., 2014) and as much as 43 percent under agroforestry, according to estimates (Nair et al., 2009; Zomer et al., 2014).

Certain regions are lagging far behind, however, most notably sub-Saharan Africa and Southeast Asia. These areas face the greatest demand to increase food production due to their low current production levels combined with some of the highest rates of population growth in the world. Traditional methods such as zaï, implemented by local communities with support from the International Union for Conservation of Nature (IUCN), help develop sustainable agriculture based on living soils.

Restoring soil biodiversity and reviving ecosystem services is necessary to reverse land degradation, which is costing up to $10.6 trillion every year, equivalent to 17 percent of global gross domestic product. These efforts increase soil’s resilience and ability to rebound to functional health after a severe disturbance. Wider society also benefits when farmers help conserve soil biodiversity: healthy soil mitigates climate, makes food production more resilient, and reduces the risk of drought and flood. These benefits may hold the key to promoting good practices and a shift towards large-scale adoption of more sustainable land management.

Sustainable farming methods conserve biodiversity both above and, crucially, below the earth’s surface. This is especially important in dryland areas. Underground-dwelling creatures play a vital role in infiltrating and storing moisture. They also accelerate the decomposition of plant residues, converting organically held nutrients into mineral forms, like nitrogen, available for renewed plant uptake.

As global momentum to conserve drylands gathers in Inner Mongolia this week, we are reminded that these ecosystems are crucial to sustaining the global food supply and mitigating and adapting to climate change. One global goal that countries are striving to achieve to this effect — Land Degradation Neutrality — will directly depend on changing the way the agricultural sector conserves soil biodiversity. The goal, which aims to maintain or even improve the amount of healthy and productive land resources over time, has multiple benefits, simultaneously addressing food and water security, climate change mitigation and adaptation, and biodiversity conservation. It feeds directly into the Sustainable Development Goals and the Paris Agreement on climate change. But it will fail without appropriate policy and investment mechanisms to conserve soil biodiversity.

More attention is also required from national policy makers to encourage farmers to protect and increase soil organic carbon — the microbes, fungi, and invertebrates, as well as root matter and decomposing vegetation, found in soil. Soil organic carbon is used as a principle indicator of land degradation. It contributes to the fertility of the soil and to its capacity to hold water, determining the soil’s capacity to produce food and to support other biodiversity. Many countries lack the facilities to routinely monitor soil organic carbon, which tends to be treated as a useful by-product rather than an explicit objective of sustainable land management. At the same time, some agricultural practices lead to large losses in soil organic matter that are not monitored or regulated, despite the major cost they represent to society.

The benefits of sustainable land management, and of conserving soil biodiversity, are felt across multiple sectors, including agriculture, water, cities, and wildlife, and may not be effectively safeguarded if they are made the sole responsibility of one sector. Policies are needed to guide investments that provide multiple benefits and these benefits need to be monitored and rewarded.

The importance of conserving soil biodiversity is becoming clearer thanks to dialogue at the UNCCD conference in Ordos, although it is well understood by millions of farmers around the world.

Pacodé Savadongo is among the villagers of Tougou, Burkina Faso, who have struggled to feed their families in the challenging dryland conditions. “Practices like zaï help us live better,” he says.