Desertification is the degradation of land in arid, semi-arid and dry sub-humid areas, primarily caused by human activities and climatic variations. Local conditions often mean that only a very low population density can be supported without damaging soil fertility. Although other regions, mostly in Asia and Latin America, are also concerned, the most dramatic examples of desertification are found in Africa, where declining soil fertility is linked to declining agricultural productivity. But this cycle is not inevitable.
Soil fertility helps in several ways. High levels of soil organic matter improve water retention. Furthermore, fertile soils can support a more vigorous crop cover, which can help prevent erosion that contributes to desertification.
Since 1998, IFA has been involved in a multistakeholder partnership to address this issue through improved soil health in seven West African countries.
The emphasis has been on improving land productivity by enhancing farmers' access to improved technology and inputs, especially credit and mineral fertilizers. Farmers learn to combine locally available organic resources and mineral fertilizers to build up soil fertility and to improve fertilizer use efficiency, an approach known as integrated soil fertility management (ISFM). In this case, mineral fertilizers are seen as a way of increasing the supply of available organic matter.
Soil fertility technologies are part of a holistic method that teaches farmers business skills and how to conduct agronomic experiments on their own. The project also addresses the need for an enabling market system, with access to credit, timely delivery of appropriate inputs and opportunities to sell produce. The results have been striking–more than 60,000 farmers have participated to date and increased their incomes as a result of increased soil fertility.
The Dust Bowl era in 1930s North America highlighted the importance of protecting soil fertility to prevent environmental, economic and social disaster. Little or no replenishment of the nutrients mined from the soil by intensively cultivated crops was a key factor in this disaster.