|Powell, J Mark|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2003
Publication Date: 3/20/2004
Citation: Powell, J.M., Pearson, R.A., Hiernaux, P.H. 2004. Crop-livestock interactions in the west African drylands. Agronomy Journal. 96:469-483. Interpretive Summary: Most dryland farming systems of West Africa integrate crop and livestock production. Pearl millet, sorghum and maize are the principal cereals, fonio is important in some areas, and rice is cultivated in delta areas and along river and stream borders. The legumes cowpea and groundnut are both subsistence and cash crops. Household livestock holdings range from a few to hundreds of head per household with varying ratios of cattle, sheep and goats. Although most agricultural products are used for subsistence purposes, some outputs of rangeland (wood, bush straw, fruits), cropland (grains, crop residues, legume hays), and livestock (animals, milk, meat, skins) are sold. Crop residues are vital livestock feeds during the 6 to 8 month dry season, and manure enhances soil fertility for crop production. Natural forages from rangelands and fallow lands provide important livestock feeds, and through manure, nutrients for cropland. The principal challenge facing agriculture in this region is how to achieve sustainable increases in crop and livestock production with limited use of fertilizers and feed supplements. The climatic and socioeconomic changes occurring are rapidly transforming traditional, extensive crop and livestock management practices, based on shifting cultivation and transhumance, to more settled forms of production. This review provides a synopsis of the principal biophysical and socioeconomic interactions between crops and livestock and strategies to improve the productive capacity of mixed farming systems in West Africa.
Technical Abstract: Many semi-arid regions of Sub-Saharan Africa (SSA) are experiencing vast increases in human population pressure and urbanization. These augment the demand for agricultural products and have led to the expansion, intensification and often-closer integration of crop and livestock production systems. The transition of crop and livestock production from the current relatively extensive, low input/output modes of production to more intensive, higher input/output modes of production presents numerous challenges to the achievement of required long-term production increases from these farming systems. This paper provides an overview of the challenges facing agricultural production in semi-arid SSA with a focus on West Africa. A description of mixed crop-livestock farming systems and their evolution is followed by an overview of the principal linkages between crops and livestock: income, animal power, feed and manure. The most detailed discussions relate to nutrient cycling in these farming systems. Most livestock derive their feed almost exclusively from natural rangeland and crop residues, and livestock manure is a precious soil fertility amendment. However, most farmers have insufficient livestock and therefore manure to sustain food production. Nutrient harvests from cropland often exceed nutrient inputs and soil nutrient depletion is a principal concern. The paper concludes with a discussion of strategies that may improve the productive capacity of these mixed farming systems.