作物生长与土壤水氮运移联合模拟的研究Ⅰ——模型

在前人研究成果的基础上，构建了土壤-作物系统农田水氮运移及作物生长联合模拟模型SPWS。模型中，采用了FAO的气象模型来完成参考作物潜在蒸散的计算，直接引用美国HYDRUS1D模型来完成土壤水热运移的数值模拟，并利用改进的溶质运移方程来实现土壤氮素迁移转化的模拟，利用改进的荷兰PS123模型实现了作物生长发育进程、干物质生产、干物质分配及光温条件下作物产量的模拟。通过对叶面积指数、根系吸水的模拟，得到了水分限制下的作物产量；通过对作物需氮量、土壤供氮量及作物实际吸氮量的模拟，得到了水氮限制下的作物产量。

Coupled simulation of crop growth with soil water-heat-nitrogen transport Ⅰ. Model

Based on the research findings given by previous researchers, a model coupling the soil-plant system with water and solute transport(SPWS model) was established. The model was comprised of four modules:soil water, soil heat, soil nitrogen and crop growth. The Penman-Montheith method was used to calculate the crop reference evapotranspiration. The method for simulating the water movement and heat transfer was directly introduced from the HYDRUS1D model. The simulation of nitogen transport was realized by utilizing the modified convection-dispersion equation of the HYDRUS1D model. The improved version of PS123 moel was applied to simulate the growth process of crop, production of dry matter, allocation of dry matter and crop production of light and heat. The crop yield under water stress was obtained from the simulation of leaf area index and root water uptake. The crop yield under water and nitrogen stress was calculated based on the simulation of the nitrogen demand of crop, nitrogen supply of soil and nitrogen uptake of crop.