Farmers' knowledge and management of spatial soil and crop growth variability in Niger, West Africa

Abstract

A household survey conducted in the Sahel, combined with an extensive literature search of baseline studies, complemented on-station research on spatial soil and crop growth variability from a farmers viewpoint. Farmers explained spatial variability in crop growth in terms of differences in soil types, soil fertility and degradation, as well as their cultivation and management practices. Farmers counteract spatial crop growth variability by within-field fallow; kraaling; spot applications of manure, crop residues and household waste; by intentionally moving their settlements; and by exploiting the micro-environmental differences around specific tree and shrub species. However, these strategies also enforce the spatial crop growth variability. The accuracy of farmers' comprehensive knowledge of agriculture, soil, animal husbandry and agro-forestry was confirmed by compartmentalized on-farm and on-station studies conducted in the same region, although explanations of farmers and researchers were not always the same. Farmers are aware of soil fertility management technologies, either coming from outside or developed within the farming community, but are often unable to translate these into action on a large scale. This is due to insufficient resources and socioeconomic, as well as institutional, constraints such as cattle ownership, land tenure, labour requirements and prices of inputs. Implications for agricultural research and technology generation are discussed.