Comparative Analysis of the Current and Potential Role of Legumes in Integrated Soil Fertility Management in West and Central Africa

Abstract

Legumes play an important role in farming systems in East Africa. Legumes are not only a source of food and fodder but also play a key role in improving soil fertility. As a result of the increasing pressure on land, the traditional fallow periods needed for land regeneration have shortened. Similarly, most farmers in the region do not use fertilizer. As a result of this, the soil fertility is low and declining. Whereas the nutrient deficiencies can be resolved by use of inorganic fertilizers, most smallholder farmers are poor hence cannot afford to purchase fertilizers. In other instances fertilizer is not accessible due to poor infrastructure. The use of farm yard manure on the other hand is limited since most farmers do not have livestock and where the manure is available, it is of poor quality. The growing of legumes which fix nitrogen and improve other soil properties emerges as a potential solution to the soil fertility problem among the smallholder farmers. Research in the region has identified a wide range of legumes that can be incorporated in the cropping systems. These include grain and herbaceous legumes either grown in rotation or together with cereals. The legumes however, vary in their rate of growth, susceptibility to diseases and pest, adaptability to given agroecological conditions, ability to fix nitrogen and general acceptance by the farmers. Althugh the benefits of legumes are recognized and promoted in many parts of the world,, their use in East Africa is still low. This can be attributed to among other reasons diminishing land holdings, low and declining soil fertility, unavailability of improved germplasm, low and lack of proper agronomic knowledge on legume production, pest and diseases, poorly developed input-output markets among others. Strategies to increase legume production should aim at identifying niches for these legumes in both space and time; assessing their ability to fix N under on-farm conditions and to demonstrate immediate benefits such as substantial increase of food crops, fodder and wood products and cash to the farm. This chapter discusses the trends in legume production in East Africa and the role played by legumes in integrated soil fertility management (ISFM).