AquaCrop Model Application Of Summer Maize Planting In North China

North China is an important grain production base, and the shortage of water resources has seriously hampered the development of agricultural production. To make use of limited water resources to develop agricultural production and receive a higher output, it is necessary to understand crop water response mechanism and rainfall or irrigation to grow in different conditions on crop growth and yield clearly so as to make full use of existing water resources to improve crop production and yield. This makes revealing microcosmic crop water response mechanism and macroscopically quantitative analysis an important part of solving a serious shortage of water resources and achieving regional sustainable development in North China. Yet to forecast output is becoming increasingly important in the optimization of limited irrigation water to enhance sustainable agriculture. It is not only provides an important theoretical basis for planning and designing water-saving irrigation system, assessing water management decision-making, optimization of non-sufficient irrigation water distribution and establishing irrigation schedule, but also guides agricultural production and the rational development and utilization of water resources with an important guiding significance.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. The farmland observation data,being the base of this research,are obtained at Hengshui Experimental Station of Institute of Dryland Farming and Water-saving Agriculture, Hebei Province Agriculture and Forestry Academy. This station is the representative of North China. 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 North China Plain by comparing the simulated productivity and the measured productivity in 2007. Research results are as follows: 1. Based on Hengshui summer maize field experiment in 2008, 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 summer 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 error (RMSE) range of simulated soil water balance is between 0 and 0.058, that of crop productivity between 0.034 and 0.065 and that of water use efficiency simulation between 0.004 and 0.099.2. The model parameters suitable for Hengshui area after debugging are that maximum canopy cover is 90%, root maximum possible expansion rate 2.80 cm/day, shape factor of expansion of root zone when crop is water stressed -5, shape factor of adjustment of Kcbx when senescence is triggered 0.13, decrease with p(sen)once senescence is triggered 12%, reference depletion factors 0.5, adujstment depletion factors by ET0 1.3, Reference Harvest Index 48% and Threshold green canopy cover below which Harvest Index can no longer increase 11%.3. Through the input parameters sensitivity of the model, the cycle of building up HI and the date of canopy starting to senescence of crop parameters affect yield and biomass remarkably, as well as soil layers depth, FC and CN.4. Paper simulates the process of summer maize transpiration and soil evaporation with the parameterized AquaCrop model in 2008. And the object of dividing crop transpiration and soil evaporation with little data is arrived.5. Parameterized AquaCrop model is used to simulate summer maize productivity in 2007. The results show that the simulation effect of the model are better, and it is fit to apply in Hengshui.6. The range of productivity increasing between different treatments shows that Zhengdan 958 is more suitable to irrigate 1 time in almost well-balanced year .