Aquacrop Model Application Of Maize Planting In Jinzhong Basin

Drought and water shortage is a major limiting factor for agricultural development, based on the model predictions of crop water productivity has gradually become an important tool for the efficient use of water resources in arid, semi-arid areas, the application of crop models to predict crop productivity to guide agricultural production, a reasonable development and utilization of water resources to achieve regional sustainable development and have an important guiding significance. With the continuous development of science and technology, domestic and foreign experts and scholars have established many studies of crop growth models and systems, but are limited to the research stage, be able to promote a wide range of model less truly user-oriented, simple and practical, and most of the model required data more and more detailed, thus limiting the promotion and application of crop models in the actual production. Research and development AquaCrop model for the above problems and to achieve the multiple objectives of the crop growth simulation with less data by FAO, the separation of crop transpiration and soil evaporation, the prediction of productivity, optimize the irrigation system, more intuitive, a wide range of the application object is a truly user-oriented, simple and practical model.The studies on the exploitation and application about AquaCrop model are much more in foreign countries but much less in China, and it has no relational papers on this model especially whether the model is suitable for predicting crop productivity and optimizing the management in China and it have been applied only in the North China Plain. The farmland observation data, being the base of this research, are obtained at Dry Farming Research Center of Shanxi Province Academy of Agricultural Sciences. These stations are the representative of Jinzhong basin. It takes crop water response model AquaCrop excogitated under the leading of FAO as a tool, and model parameters are estimated or optimized according to meteorological data, soil moisture data and crop data investigated of Experiment Station from the year 2008. Then we can use the parameterized AquaCrop model simulate crop transpiration and soil evaporation to study if the AquaCrop model suits the application of the Jinzhong basin by comparing the simulated productivity and the measured productivity in2009and2010. Research results are as follows:1. Based on Yuci spring maize field experiment in2008, with the application of meteorological data, soil moisture data of different irrigation schedules and crop data for debugging AquaCrop model, local model parameters suited to simulate spring maize productivity are obtained. The results of their testing is that the changing trend of simulated values is consist to that of measured values on canopy cover and soil water content, and the average relative error range of simulated soil water balance is between0.043and0.097, that of crop productivity between0and0.138, and that of biomass and yield is0.05and0.65.2. Through the input parameters sensitivity of the model, planting density, to reach CCx time, the date of canopy starting to senescence and crop maximum effective rooting depth of crop parameters affect yield and biomass remarkably, as well as FC, initial soil water content and CN.3. The model parameters suitable for Yuci area after debugging are that maximum canopy cover is between90%and94%, the value of Z and Zr is1.8and0.3meters, root maximum possible expansion rate2.1cm/day, shape factor of expansion of root zone when crop is water stressed-4, shape factor of adjustment of Kcbx when senescence is triggered1.03, Reference Harvest Index48%, the value of the soil surface evaporation of water is7mm, soil moisture stress on canopy expansion affect the upper limit of soil moisture loss of0.11, lower limit of0.72, soil water stress on stomatal opening the upper limit of0.69, the accelerated canopy senescence affect a maximum of0.67and the maximum flowering pollination failure of0.77.4. Based on the parameterized AquaCrop model in Sizhuang village field trials in2009, the regression coefficient b (through the origin) between the simulated and measured values of the spring maize canopy growth process are close to1, the coefficient of determination R2in addition to T7are up to0.81above, the root mean square error between0.034and0.069, model performance index EF except for T3and T7also reached above0.85, biomass and yield root mean square error RMSE range between0.025and0.086, the model performance index EF reached above0.93. simulation Hecun village field trials in2010, spring maize canopy coverage of the simulated and measured values of root mean square error between0.154and0.293, the model performance index EF between0.69and0.802, biomass and yield root mean square error (RMSE) range between0.021and0.058, the model performance index reached above0.94, and that of water use efficiency simulation between0.054and0.12.5. In general, the actual production conditions in the Jinzhong basin is reflected by simulation results of AquaCrop model, simulated and measured values has reached a reasonable range in addition to the simulated canopy cover in2010. The model can be applied to the Jinzhong basin in maize cultivation research by simulation of high accuracy and good overall performance.