We must make up ground in the fight against desertification

A global partnership is needed to tackle the desertification that degrades more than 12m hectares of arable land every year, affecting some of the poorest and most food-insecure people

The 193 nations party to the United Nations Convention to Combat Desertification (UNCCD) will gather in Changwon in Korea on Tuesday and Wednesday this week to discuss what can be done to address challenges related to land degradation and drought.

Despite successive warnings and tree-planting campaigns in Sahel and other degraded arid lands, desertification is still progressing fast. More than 12m hectares of productive land are lost every year, the equivalent of losing the total arable area of France every 18 months.

Preventing irreversible degradation should be a global fight tackled with local, national and regional solutions. One-third of the world's population lives in drylands where land degradation is reducing food supplies, biodiversity, water quality and soil fertility. Many of the poorest and most food-insecure people live off these lands as small-scale farmers and herders. Because they have no fallback options if this land deteriorates, they are the worst hit by desertification.

At the recent UN general assembly meeting on desertification and drought, UNCCD executive secretary Luc Gnacadja said: "If we do not take bold actions to protect, restore and manage land and soils sustainably, we will not alleviate rural poverty and hunger, ensure long-term food security, build resilience to drought and water stress. This will lead to consequences including more political conflicts over scarce resources and continued forced migrations."

The meeting proposed the establishment of a scientific advisory panel on land and soil degradation. Science is essential to identify the drivers of desertification and highlight the most appropriate actions to stop it. Donors must have a clear idea of how big the problem is and feel confident that progress in overcoming the desertification problem can be measured.

Solutions exist to help communities living in harsh environments to improve their livelihoods. The International Crops Research Institute for the Semi-Arid Tropics (Icrisat) is working with local, national and international partners on initiatives that revitalise soils and conserve water, enabling communities to reap the health benefits and incomes from otherwise degraded or soon to become degraded lands.

The approach of bioreclamation of degraded lands shows how women's groups could revitalise barren lands by using simple water and soil conservation techniques, such as zai pits (small holes enriched with compost), to plant drought-tolerant trees and crops, and applying small amounts of fertiliser to the plant root, a technique known as microdosing.

In west Africa, most women have no or few rights to agricultural land, so Icrisat has been working with local NGOs to help them form associations and gain access to communal village wasteland. Scientists showed the women how to plant a range of crops, nutritious trees and high-value vegetables using zai pits and demi lunes (semi-permanent planting basins) to harvest rainwater and concentrate nutrients for the plants.

Their work shows that degraded lands can be made productive by plants such as the hardy Pommes du Sahel, which have 10 times the vitamin C of ordinary apples and are rich in calcium, iron, and phosphorus, and Moringa trees, the leaves of which contain four times the vitamin A in carrots, four times the calcium and double the protein in milk and three times the potassium in bananas. Drought-tolerant pigeonpea was found to help soil fertility by fixing nitrogen in the soil. It also traps pests that would otherwise attack and damage the okra that the women plant in the zai pits, and gives harvests even when rainfall is scarce.

However, most crucially, we must look at how we can prevent soils becoming degraded in the first place. By involving farmers in sustainable water and soil management, Kothapalli, a village in Andhra Pradesh, India, which was previously below the poverty line due to recurrent drought, is now prosperous and serving as a model for other villages in Thailand, Vietnam, China and Africa. Farmers have been shown how to carry out a healthcheck and feed it the nutrients that are missingso that the soil recovers before it is too late. By adding nutrients such as zinc and boron to exhausted soil, farmers are getting better and more nutritious harvests.

But we need a global partnership between governments, experts, civil society and local populations to scale-up successful projects. We also need a transparent debate about the roots of desertification if we don't want to spoil the land we borrow from our children.

William Dar is director general of the Icrisat in Andhra Pradesh, India