Effects Of Gravel-soil Mulching On Soil Evaporation In Gravel-Mulched Land

This paper focuses on the process of soil water evaporation is not clear of Zhong wei Xiang shan region in Ningxia, using field experiments to study the effects of soil moisture evaporation from different gravel soil covering measures and gravel soil mixing ratio, the main conclusions are as follows:(1) According to the analysis of thogonal on soil evaporation threshold, the result shows that the important torder of test factors for soil evaporation threshold is:rainfall> gravel soil mixing ratio> covering thickness, among which rainfall is highly significant influence factor, gravel soil mixing ratio is the significant factor, gravel soil covering thickness is the secondary factor.(2) According to the fitting analysis and linear fitting of least square method of soil cumulative evaporation under different rainfall, gravel soil covering thickness and gravel soil mixing ratio.the results show that it all can use logarithm function to represent the relationship between soil cumulative evaporation and time, the correlation coefficient of rainfall is all greater than 0.83.(3) According to the analysis of different rainfall, gravel soil covering thickness and gravel soil mixing ratio of the soil moisture content change process, finds that the soil moisture content change along the time with the increase of rainfail and gravel soil covering thickness and gravel sand mixing ratio decrease, the inhibitory effect is more significant as the covering thickness is incresed, when the gravel soil mixing ratio increases to 100%, the Changes of soil moisture content for five treatments are consistent, it illustrates that the best inhibitory effect is gravel covering.(4) Using the least squares method to analysis the similarity between the theoretical and actual evaporation threshold under different rainfall,gravel soil covering thickness,mixing ratio, the results show that it can use polynomial function to represent the relationship of soil water evaporation threshold with rainfall,cover thickness,and the mixing ratio, the correlation coefficient is greater than 0.89.This research results for Optimization of irrigation system and restoration of ecological environment provides data suppor, and promotes the sustainable development of agriculture in gravel-mulched land.