Two-Dimensional Experiment And Simulation Of Soil Water Movement To The Cropland In Arid Area

The economics of Xinjiang Uygur Autonomous region has developed rapidly,then ecological environment is deteriorating.All these have become an important factor that threatens the development of oasis economy,which has aroused great attention from the society.Because of its unique geographical environment,Xinjiang has made oasis agriculture one of the important factors to control the economic development of Xinjiang.In recent years,oasis agriculture has developed rapidly,drawing on domestic and foreign research experience and achievements,on the basis of straw returning policy,research new method on returning straw to field.The objective of this subject is mainly to optimize soil structure and improve the efficiency of farmland irrigation.The method of this study combined two-dimensional indoor testing and HYDRUS-2D software together,to analysis the condition of the soil water movement under straw returning.The conclusions of the study are as follows:1.Straw returning can improved the physical properties of the soil,thus changing the water conductivity and water holding capacity.of the soil.2.The influence of mixing ratio and returning depth of the mixture on soil water infiltration is different,The influence of mixing ratio and depth of mixed products on soil properties is different,which leads to the difference of cumulative infiltration rate,infiltration rate,wetting front movement and soil volumetric water content under different returning conditions.Comparing the treatment of different blending ratios,the results showed that the greater blending ratio,the more effective.3.In the experimental study,the wetting front is turns to be stabilized,and the distance in the vertical direction is slightly larger than the horizontal direction;the cumulative infiltration volume increases with the infiltration,but the increased rate gradually decreases,and finally tends to stabilize;however,when the depth is 0-30 cm or 0-40 cm,the infiltration rate is move up and down.4.In order to find the optimal straw returning amount and depth,analysis ofinfiltration in different infiltration groups during infiltration.The study found that when the proportion of straw mixed in the soil was 10%,and the depth of straw is0-30 cm,infiltration rate is moderate,and the medium and high soil volume distribution area is uniform.5.With HYDRUS-2D software,the soil water characteristic curve was numerically simulated and combined with the measured data to select the optimal empirical model.The soil water characteristics curve obtained from the simulation presented a trend of rapid decline-slow decline-basically stable,and it conformed to the basic law of soil water characteristic curve.6.The HYDRUS-2D model was used to simulate the process of soil water infiltration,and the final results were obtained by simulating parameters corrected by measured values.Simulated wet front and measured wet front error within0.25 mm.The fitting degree of the selected straw returning method and the measured soil volumetric water content was over 85%,so HYDRUS model has better applicability in the area.From the microscopic point of view,based on the theoretical basis of soil hydrodynamics and the physical mechanism of soil water transport,then combined with the returning of straw to the soil,through a soil box that simulates the soil environment,Comparative and analysis of the effect of different straw straw mix on soil water infiltration characteristics,we get a model of soil water movement based on HYDRUS,which provides a basis for the regionalization of soil water,thereby improving the utilization of water resources and providing references for soil improvement.