Simulative Evaluation of the Response of Maize and some Dual-Purpose Legumes to Water and Nutrient Amendments

Abstract

The study evaluated DSSAT's CERES-Maize and CROPGRO models for their effectiveness in simulating the growth of maize, groundnut, and cowpea under dynamic nutrient amendments and water management practices in field experiments. The experiments were laid-out in split-plot with water management (rainfed and irrigated) as main plots and fertilizer (organic and inorganic fertilizer) as sub-plots during the maize trial, while, water management treatment (irrigated and rainfed) was the main plot and variety as the subplot during the cowpea and groundnut trials arranged in three replications. The CERES-Maize model's RMSE-observations standard deviation ratio (RSR) for simulating maize grain yield under irrigated and rainfed were 0.1624 and 0.0317 respectively, while that for the maize biomass under irrigated and rainfed were 0.4027 and 2.1676 respectively. Also, the CROPGRO model's RSR for simulating groundnut grain yield under irrigated and rainfed were 0.1058 and 8.0592 respectively, while that for the groundnut biomass under irrigated and rainfed were 1.1154 and 0.0161 respectively. In addition, the CROPGRO model's RSR for simulating cowpea grain yield under irrigated and rainfed were 8.1625 and 0.1019 respectively, while that for the cowpea biomass under irrigated and rainfed were 0.2677 and 0.2630 respectively. From the results, it was concluded that the CERES-Maize model was more suited to effectively scope alternate management practices under maize production whereas more research is needed to be able to confirm the effectiveness of the model in our environment.
Keywords: Crop production, CROPGRO, CERES-Maize, DSSAT