Application of rainfall analysis, biophysical modeling and GIS to agroclimatic decision support in Madiama Commune, Mali (West Africa)

An analysis and understanding of the intimate relationships between the weather, soils and agricultural production systems, and especially the complexities associated with the variability and distribution of rainfall and soil type are essential elements in improving crop production and agricultural planning decision making. In the present paper, knowledge from the analysis of historical rainfall records and predictive information based on the "response farming" approach have been combined with GIS and biophysical simulation modeling of soil water balance and crop production functions to assess the agroclimatic performances of a 90-day millet cultivars in Madiama, Mali. For each of two groups of rainfall onset date (early and late), the crop water stress, crop yields as well as overall stress indices in reference to yield potential permitted by different soils under low and optimum nitrogen input levels have been simulated, analyzed and mapped to illustrate how this approach could work for advisors and farmers in the study region. From the analysis of the rainfall records good relationships are found between rain onset dates and seasonal rain amounts and duration. Also, the Cropping System Simulation Model (CropSyst) used in combination with the weather analysis is found to be a useful tool in aiding determine soil suitability of crops, screen technologies and build recommendations packages for a response farming type approach.