The Optimization Of Soil Water And Nitrogen Management Of Winter Wheat

Based on studying of the crop growth models, a simulation model of crop growth model was established with computer languages. Union the model and the soil module which based on hydrodynamics and solute transportation, meteorological module, a whole join soil-crop model is used to simulate the dynamic growth of the crop under the soil water, nitrogen, heat and meteorological factors.The verification and validation of the model has been conducted by experiment data in Hebei province Quzhou county in 1998~2000. The results showed that the simulation outcomes are very similar to the experiment data, and the crop growth model possesses quite good simulation function. It can simulate winter wheat growth biological and ecological processes such as photosynthesis, respiration, dry matter production, yield and leaf area dynamic, etc, under different climate and soil conditions. The model can provide abundant output, and it can reflect winter wheat growth and develop for simulated conditions.Using the amounts of irrigation and N as the programming variables, the yield and the use efficiencies of water and nitrogen resources as the optimization goal, a dynamic multiple goal programming model was established. Water and nitrogen management was optimized with the dynamic programming method.Through the calculation of the water stress index and N stress index, when and how much irrigation and fertilization can been decided. The optimized results showed that when higher yield is being wanted, the model can maintain good use efficiencies of water and nitrogen at the same time to reach the goals of saving resources and protecting the environment.