Effect Of Salt Crust On Soil Physical And Chemical Properties And Factors Of Thickness Variation In Ebinur Lake Wetland

Soil salt crust(SSC)is widely found in nature and can exert certain influence on soil physical and chemical properties and ecosystem in arid wetlands.However,soil physical and chemical properties and climate change can promote or inhibit the formation and development of salt crust.They interact and influence each other.Finally,it will affect the stability of lake wetland ecosystem in arid area and play a key role in regional sustainable development.So in this paper,we study the ebinur lake wetland soil physical and chemical characteristics of spatial variation characteristics and the relationship of the salt crust,and the main factors that influence the formation and development of salt crust,revealing the salt crust soil physical and chemical properties of wetlands in arid areas space change and the influence of the vertical change mechanism,can provide new governance for the current situation of the ebinur lake wetland shrinking method,It can also be used as a reference for the restoration of other wetlands in the arid area,which has practical effect and practical significance for the sustainable development of local society.Based on the thickness of salt crust,soil type and topographic environment,this study took Ebini Lake wetland as the research area.Based on the method of geostatistics,the study was divided into the Ala Pass area(A area),the northern Ebini Lake area(B area)and the southern Ebini Lake area(C area).Using GIS+5.0,Morani coefficient and Kriging spatial interpolation,By comparing the physical and chemical properties of soil covered with or without salt crust with the theoretical model of variation function,the autocorrelation relationship and spatial variation characteristics of soil physical and chemical properties were determined.Finally,principal component analysis is used to analyze the main influencing factors of salt crust thickness.The results showed that:(1)Soil bulk density,soil particle size,mass water content,porosity,total salt and pH under salt crust mulching were all higher than those without salt crust mulching,while organic matter,total phosphorus and total nitrogen were all lower than those without salt crust mulching.However,the spatial variability of soil physical and chemical properties under salt crust mulching is weaker than that of soil without salt crust mulching,which is less affected by randomness and surrounding space factors.(2)The soil total salt,pH,bulk density,porosity,mass water content and grain size(0.05-1mm)of 0-20 cm soil covered with salt crust were all higher than those of soil without salt crust.Soil organic matter,total phosphorus and total nitrogen were all lower than those in the soil without salt crust.The total salt,pH,bulk density and mass water content of the soil covered with salt crust were all higher than those of the soil covered with salt crust at 20-40 cm depth.The organic matter,total phosphorus,total nitrogen,total salt,pH and grain size groups were similar to those of the soil without salt crust.The vertical change range of soil physical and chemical properties under salt crust mulching is small,and the correlation between salt crust thickness and soil physical and chemical properties decreases gradually with the increase of depth.(3)In soil physical properties,soil capillary porosity(0.78)accounted for the largest proportion,followed by soil grain size(0.01-0.001mm).With the increase of soil porosity,soil salt crust thickness increased,while with the increase of soil grain size(0.01-0.001mm),soil salt crust thickness decreased.In terms of soil chemical characteristics,soil total salt(0.962)accounted for the largest proportion,followed by soil total phosphorus(0.724).The thickness of soil salt crust increased with the increase of soil total salt,and decreased with the increase of soil total phosphorus.Soil porosity and total salt promoted the growth of salt crust,while grain size(0.01-0.001mm)and total phosphorus inhibited the development of salt crust.According to the comprehensive natural factors,the porosity(0.968),capillary porosity(0.942),precipitation(0.911)and soil grain size between 0.05-1mm(0.903)in the first principal component can promote the formation of salt crust.The second principal component,total soil salt(0.924)and average air temperature(0.817),were the main factors for the increase of salt crust.Soil organic matter(0.779)and total phosphorus(0.715)in the third principal component could inhibit the growth of salt crust.Average wind speed in the fourth principal component(0.703)will restrain the growth of the salt crust,the overall soil porosity,the greater the rainfall,the soil particle size is larger,the higher the temperature will promote the emergence and development of salt crust,its thickness will increase,the greater the soil organic matter,total phosphorus content,the greater the wind speed will restrain salt crust,its thickness decreasing.