Science et changements planétaires / Sécheresse


DHC software programs to assess crop production in terms of moisture status : forecasting millet yields in Sudano-Sahelian areas of West Africa Volume 9, issue 4, Décembre 1998

  • Page(s) : 281
  • Published in: 1999

This study describes the practical use of a software program that processes information on water resource supplies and interactions with crop production in semiarid Sudano-Sahelian areas. This deterministic model produces early assessments, i.e. 1-2 months before harvest, while explaining soil-water-plant-atmosphere interactions and crop production mechanisms. Crop yield determinations are based on real evapotranspiration (RET) measurements for productive flow. In agroclimatology, this parameter provides an efficient basis for understanding crop yield structure. Many studies have shown that 70-90% of cereal yield increases in the Sahel region can be explained by water-resource optimization. The crop production potential can be assessed much before the harvest period by monitoring rainfall and cropping conditions during the rainy season. This is essential in CILSS countries for two reasons: 1) humanitarian, as rural populations (i.e. more than 70% of the total population in each of the nine concerned countries) depend mainly on rainfed crops to fulfil their food requirements; 2) economic, as it facilitates food trade management. The DHC software package estimates the RET parameter via Eagleman’s algorithm, and crop yield on the basis of crop water supply. Examples of its application are given in the present paper. The program has been improved through input data interpolation, the use of remote sensing data and geographical information systems (GIS). Further improvements are planned, e.g. applications to a wider range of crops and taking soil fertility and water surplus into greater account.