Agroclimatic analysis for reducing planting risks in Burkina Faso and Senegal

This study was carried out in Burkina Faso and Senegal, West Africa. The purpose of the study was to (i) characterize the climate and assess the occurrence of meteorologically below average rainfall years, (ii) evaluate the rain onset, cessation, and length of growing period, and (iii) identify the optimal planting time for maize, sorghum, pearl millet and peanut. The study showed that there is a latitudinal difference in rainfall distribution and frequency from south to north in both Burkina Faso and Senegal. Over the past 40 years period (1981–2020), at least 6 years were identified as meteorologically drought years with a spatiotemporal variation in the severity. The most severe one occurred in 1983–84. Occurrence of below average rainfall substantially reduced after 1990 for both Burkina Faso and Senegal. The number of rainy days with rainfall values ≥ 5 or ≥ 10 mm for each growing seasons in both Burkina Faso and Senegal were highly correlated with the annual total rainfall. The lowest and highest rainfall values corresponded to northern and southern locations, respectively. Planting based on onset estimated by weekly cumulative rainfall probabilities in three out of four years meeting 50% weekly cumulative reference evapotranspiration enhanced yield and found to be suitable planting for sorghum, maize, millet and peanut in the south and central part of both countries. Yield followed the spatial rainfall and temperature gradient in both Burkina Faso and Senegal. The northern most locations were dry and thus it is not optimal to grow grain crops without irrigation.