Soil water crop modeling for decision support in millet-based systems in the Sahel: a challenge

Abstract

Food insecurity in the Sahelian environment was extensively shown to be a result of low soil fertility and high climate risks. But decisions and recommendations made from the great wealth of research have little been adopted by farmers. Soil water crop models (SWCM) can assist researchers and development actors in this environment if they can appropriately deal with the constraints and mainly farmers’ agricultural development goals. We reviewed the Sahelian agricultural constraints and farmer management practices with an emphasis on Niger and pearl millet. Significant results derived from research works to improve crop productivity are presented and analyzed with regard to the main agricultural constraints. Potential and currently used SWCMs are presented and compared for relevance for use in such a particular environment for decision support (DS). This shows that crop modeling in millet-based agricultural system of the Sahel should be addressed with an integrated approach that can handle the multiple and usually connected agricultural constraints of the region: low soil fertility and spatial variability, time and space rainfall variability. Recommendations were made regarding the relevant and minimum aspects that SWCM should take into account for a successful and reliable use for DS in the complex Sahelian environment.\r\t\r\t\t \r\t\r\t\tKey words: Rainfall variability, simulation, nutrients, climate change, climatic risks, soil fertility.\r\r\r\t