Experiment Of Microclimate Regulation And Numerical Simulation Soil Water Dynamic Of Root Zone For Jujube Orchard In Arid Region

The Modern Efficient Irrigation Technology (MEIT) is considered the best way to increase water use efficiency which combines dirp irrigation, micro-spray irrigation, bubble irrigation and percolation irrigation with Efficient Management Irrigation System. The key of using MEIT is considered reasonable irrigation schedule which formulated by using soil moisture absorption, consumption of root zone usually. This study relying on the Project Supported by National Technology"Integrated and Demonstrated Water Saving Technology of Modern Agriculture in Arid Region",the jujube is the object of study in the Aksu's Agricultural Science-technology Demonstration Park, in order to discuss the soil water dynamic and the law of water consumption under the MEIT and so on,through measuring soil water content by TRIME and Hydra system,measuring deep percolation by the tray of incepted seepage water,measuring meteorological factors by Vantage pro2 automatic meteorological station, measuring water uptake root by using root drill and so on. The diagram, mathematics statistics, numerical simulation (HYDRUS), and regression analysis were used to analysis observation data. The main research results summarized as following:(1) The variance analysis result of obtained data from different treatment show that, jujube orchard microclimate regulation experiment spraying at the center part of trees were superior than remarkable, the yield of treatment with spraying at the center part were 51%,26%,4% higher than CK, spraying at the top, spraying at the below; the yield treatment spraying 60 minutes over than CK 49%,spraying 40 minute 20%,spraying 20 minute 2%. Then differences of jujube quality among every treatment are not notable.(2) Based on the data obtained from experiment. Calculate the soil physical parameters by using the RETC software; the binary linear exponential equation was established by MATLAB software; using the right triangle subdivision to the simulated domain, and mesh refinement at the section around Variable-Flux; confirmed parameters depended on data of experiments. At last finished HYDRUS (2D/3D) method by using the upwards result.(3) Using the HYDRUS (2D/3D) method simulation of soil water dynamic in jujube root zone under drip irrigation commenced on 15 June and ended on 11 September(179days). The goodness of fit between simulation and measurement are measured by using the root-mean-absolute-error (RMAE) for the simulated with measured volumetric soil water contents. The results show that the RMAE values for the 90 day's soil water dynamics at soil layers of 20cm,60cm,80cm,100cm below drip tube are 14.2%,13.0%, 1.1%,1.0% respectively; the RMAE values for simulation section of before, after irrigation are 5.1%, 4.3% respectively. Indicating the model perform well in simulating soil water dynamic during the growing reason.(4) Using the HYDRUS (2D/3D) method simulation assumption irrigation schedules which were dissimilarity irrigation quota, irrigation times and irrigation date, the goodness of irrigation schedules are measured by percolation rate, evaporation rate and transportation rate of high and low levels. The result show that the one which irrigation quota is 45mm, irrigation times is 12, irrigation date adjustment according to phenophase and precipitation during the execution period.