The role of fertilizers in sustaining agriculture in sub-Saharan Africa

Abstract

African farmers have relied traditionally on fallowing for up to 15 years to restore soil fertility. Leaving land unproductive for such periods is a luxury many regions cannot afford, given the contemporary decline in per capita food production (1%/year). Thus, alternative soil fertility maintenance measures such as agroforestry, novel intercropping systems, residue conservation, the use of manure, soil amendments, and fertilizer have recently been given greater emphasis. The Food and Agriculture Organization (FAO) estimates that 75% of the increase in regional food production must come from intensive production. However, fertilizer use in sub-Saharan Africa is only one tenth of the world average. The small size of fertilizer markets in most countries is an important contributing factor in relatively high farm-gate prices and low fertilizer use. There is significant scope for improving the efficiency of fertilizer procurement and distribution in the region. Most countries can substantially reduce farm-gate prices by changing to higher analysis formulas, relaxing specifications, importing in bulk and bagging locally, and improving systems of distribution. Various options of fertilizer production are discussed in this context. Intensification in areas where environmental constraints are limited and surplus production can be marketed may alleviate the demographic pressures to cultivate marginal land where increased land and labor productivity is unlikely. Although substantial effort should be made to research sustainable farming system options for marginal lands, efforts in the more resilient environments should concentrate on increased crop production, using inputs where feasible. Provisions should be made for adequate support in the infrastructural, institutional, and policy spheres to transform these regions into granaries.