The 'CropSyst' (Cropping Systems Simulation Model) is a multi-year, multi-crop, daily time step crop growth simulation model, link to a weather generator ClimGin v 4 (Stockle, 1996) was evaluated for its ability to simulate growth, biomass and grain yield, water and nitrogen use of crop production of wheat cultivar (Giza 168) grown in Giza region. Field experiment was conducted involving three water regimes (irrigating at 1.25, 1.00 and 0.75 evaporation pan coefficient EPC and three nitrogen levels (144, 180 and 216 kg N/ha) in a Meddle Egypt type of environment (Giza region). Data collected from two distinct growing seasons (2004/2005, 2005/2006) were used in Calibration/ validation models. then, the model was used to predict the aboveground biomass, grain yield and ET crop. Calibration/ validation results revealed that CropSyst was able to track the aboveground biomass, grain yield, ET crop and N uptake progression throughout the season when compared with observed data from filed experiment. Statistical analysis showed a high correlation between simulated versus observed data with values of correlation coefficient (R2) between 0.93 and 0.99. Running simulation showed that increasing soil water increased simulated aboveground biomes, grain yield and ET crop while N uptake was not effected by increasing soil water. Yields were positively affected by increased N-level and maximum simulated values were obtained for 216 kg N/ha but the ET crop increase was limited. In general, the CropSyst model was useful to use particularly in long tram cropping system and climate change strategy. However future research should be dose to evaluate the model for a wider use and different condition and regions. |
