Abstract:Soil quality,soil moisture and fertilizer preservation ability,and soil nutrient uptake ability are closely related to soil physical properties.In this study,42 soil samples were collected respectively in the 0—20 and 20—40 cm soil layers from seven desert sampling plots along descending precipitation gradient in Hexi Corridor region(from Minle County to Gaotai County).Saturated soil hydraulic conductivity was measured with the tension infiltrometer in field,and bulk density,porosity,and soil particle composition were determined by general methods in lab.Results show that physical properties of the desert soils are gradually degraded.With precipitation decreasing from 360 to 100 mm,silt and clay contents are reduced and sand content is increased.Increase in soil particle size may definitely result in soil dispersion and structure destruction,further increase soil bulk density,and reduce soil porosity and water holding capacity.The variance coefficients of saturated soil hydraulic conductivity in the surface and subsurface layers are 70.0% and 86.3%,respectively,both of which are the highest among the Cv values of all the physical properties.