Assessing the Sensitivity of Maize Production on Smallholder Systems to Projected Climate Change in Nioro Basin, Senegal.

This study seeks to assess the sensitivity of maize production in Nioro du Rip basin, located in Senegal. The Agricultural Productions Systems sIMulator (APSIM) version 7.4 and Decision Support Systems for Agro-technological Transfer (DSSAT) version 4.5 calibrated and evaluated for maize were used.  The weather input data used in the crop simulation models were from 5 General Circulation Models and a 30- year baseline historic weather data, together with soil data, farmers’ management practices and crop genetic information.  Information on farmers management practices were obtained from a household survey conducted in 2007in the region and used as input data for the model as well as 45 kg N ha^-1 applied as an improved soil fertility management. Yield outcomes were analysed for significant differences between baseline yields and climate projections, among GCMs, soil type and soil fertility management options using ANOVA and Student t-test for mean separations. Both crop models simulated a general reduction in the yield of maize, though few reductions were not statistically significant. The extent of change varied between crop models, GCMs, soil types and soil fertility management. Maize yield was simulated by DSSAT to decrease by between 48 and 25% while APSIM simulated grain yield reductions was between 13 to 2%. The extent of the sensitivity of maize production to climate change is also expected to be influenced by soil management practices and soil types. The use of mineral fertilizer reduced the sensitivity of maize to climate change impact significantly and also reduced the variability in the yield of maize significantly. Maize production on smallholder systems in this region is sensitive to climate change as simulated by both models and the extent of sensitivity varied widely across GCMs, soil type and management practices used. The use of mineral fertilizer has the potential to reduce the sensitivity of maize production to climate change.