APPLICATION OF ZAI AND ROCK BUNDS IN THE NORTHWEST REGION OF BURKINA-FASO - STUDY OF ITS IMPACT ON HOUSEHOLD LEVEL BY USING A STOCHASTIC LINEAR-PROGRAMMING MODEL

Agricultural production in the northwest region of Burkina Faso is ser iously endangered by soil erosion and an overall decline in Soil ferti lity. In the past 15 years various anti-erosion methods have been adop ted in this region with quite some success. The widespread promotion l ion of rock bunds is an important example. Land conservation methods a lone without increased efforts to maintain (or to increase) soil ferti lity levels does not suffice in the long run. In this article we focus on the potential impact of a combination of rock bunds and zai a loca l technology to improve water infiltration and efficiency of manure ap plication. The analysis is carried out at farm level with a stochastic linear programming model. It includes sequential decision making to c ope with rainfall risks. The study reveals the important potential of rock bunds and application of zai; and limitations due to labour and m anure constraints. The techniques are largely applied on common fields . Changes in labour organization and use of manure have to be introduc ed before women may profit from these techniques on their individual f ields as well. The results show that the impact on farm-level food sec urity is more limited than is sometimes supposed on the basis of a sim ple extrapolation of plot-level results.