Dynamic Simulation Of Soil Water And Water Utilization Analysis For Winter Wheat-summer Maize Rotation System In North China Plain Based On CERES Model

The North China Plain(NCP) is one of the most important food production base in China, the effect of the global warming and successive overload using about water resources are both the reasons which aggravating the trend of the local water resources crisis year by year. Water restriction is one of the most important factor which restrict the local food production. In order to provide technical support for CERES model applied to production and the water precise quantitative management in winter wheat-summer maize rotation in the NCP.We established the soil water balance model(pattern balance model) using the data measured and output of the CERES-Wheat model and analysed the water saving potential of the North China Plain based on the model of CERES. Results showed as follow:(1) Systematically analysis the winter wheat-summer maize rotation using CERES-Wheat and CERES-Maize model, the simulate result showed that CERES-Wheat and CERES-Maize model were good at growth stage, yield, yield components and ground biomass, bad at nitrogen content, evapotranspiration after variety parameter correction. Therefore, further modification on water and nitrogen absorption properties, root characteristics and the model mechanism are needed to improve the systematic precision of the CERES model.(2) the soil water content between0-200cm soil layer(20cm one layer) were analysed by using CERES-Wheat and CERES-Maize model, the simulated results showed that:model can simulate the basic dynamic changes of soil water, Simulation precision of0-120cm soil layer are more accuracy compare to120-200cm soil layer. The accuracy of the soil water content needed to improved for more precise.(3)The research presented the method of pattern balance of model simulation and build soil water content pattern balance model based on this method. Regression equation of pattern balance model were remarkable between20-120cm(20cm each layer), no remarkable between0-20cm and120-200cm. calculated root mean square error (RMSE) and relative root mean square error (NRMSE) between the soil water content CERES-Wheat model simulated values and measured values,respectively. The results showed that the pattern balance equation got higher accuracy when used to simulate soil water content, and had higher stability interannual. This illustrated that the pattern balance equation can be used to quantitative simulate soil water content more accurately.(4) With the method of scene simulation, we calculated the average requisite amount of water of winter winter wheat growth period under four water treatment (T0, T1, T2T3) were189mm,264mm,298mm and319mm. The excess amount of water in Rain-fed summer maize were57mm. the average requisite amount of water during winter wheat-summer maize growth period were132mm,207mm,241mm or262mm when winter wheat under four water treatment(T0, T1, T2T3) and summer maize under no irrigation condition. Under the condition deducting the soil evaporation (ES) base on the above results, the average water demand were0mm,14mm,48mm,70mm, respectively.