Simulation of maize top dry matter and leaf area index at different applied water and fertilizer levels.

Crop simulation models are mathematical representations of plant growth processes as influenced by interactions among genotype, environment, and crop management. Evaluation of developed simulation models for management of applied water and nitrogen in field are compulsory. In this paper, the model of MSM2 (maize simulation model) was evaluated and validated based on two years experimental data. The planted cultivar was SC704 and late maturity hybrid. Three nitrogen fertilizers and four irrigation water treatments were considered for model evaluation. The model subroutines were investigated based on the measurements of soil and plant characteristics in the experiment conducted in the two years. Leaf area index (LAI) and top dry matter (TDM) production were evaluated and validated at different days after planting by measured data. Results showed that the model could predict TDM and LAI fairly well. The resulted values of model agreement index (d) and mean bias error (MBE) for all treatments showed an overall good result in two experimental years. Validation results showed the average values of d between measured and predicted TDM and LAI are 0.97 and 0.98, respectively for different treatments. Comparisons between measured and predicted values by current model indicated favorable validation.