Evaluating Ceres-Maize Model Using Planting Dates and N Fertilizer

A field experiment was conducted during the 2013/2014 season to evaluate the performance of CERES-maize model in simulating the effect of planting date (PD), nitrogen (N) fertilizer and root-zone soil water profile on growth and yield of maize (Zea mays L.) at the Univ of Zambia (15o 24 S, 28o 20 E; 1261 m.a.s.l). The experimental design was a split plot with three replicates, 3 PD (Nov 24, Dec 8 & Dec 22) assigned to main plots and 2 N fertilizer rates (112 & 168 kg N/ha) assigned to sub-plot. Phenological stages and biomass were used for model evaluation and these were observed at vegetative and reproductive stages. Soil water profiles were monitored using the Diviner Probe. PD significantly affected grain and biomass yield at P < 0.05. the coefficients of variation for grain and biomass yield were below 12% and considered efficient. the model's prediction of plant emergence, time to anthesis and maturity was good. simulation of biomass was reasonably accurate while leaf area index was less accurate due to poor d-stat. the model's simulation of grain yield was fair while soil root water availability demonstrated that substantial potential yield may have been lost due to stress.