North-south Heterogeneity of Soil Physical-Chemical Properties for Gurbantunggut Desert

The results of the investigation and the analyses of physical-chemical propertie s for aeolian sand soils across Gurbantunggut Desert show that the aeolian soils mainly consist of extremely fine sand,fine sand and medium sand,and the soil textures of the northern desert is coarser than that of the middle and southern desert.The values of φ1 of the interdunes and the mean grain sizes of the dune-tops are respectively the highest in the different parts of those individual sand dunes.The sorting of the aeolian sand soils in the northern desert is poorer,and the skewness is extremely positive and the kurtosis is very leptokurtic.The sorting of the aeolian sand soil in the middle and southern desert is medium and better and the skewness is near symmetrical and the kurtosis is leptokurtic.The salt contents of the aeolian sand soils within the desert are all lower and the values of pH are medium.The salt contents and pH of the aeolian sand soils,whose sand surfaces are more stable,are higher.The contents of organic matter,total N and P of aeolian sand soils are all poorer,and the contents of total K mostly belong to med ium lever.The contents of total K and organic matter for aeolian sand soils in the northern desert are higher than that in the middle and southern desert.The contents of organic matter,total N and P in the interdunes and dune-slopes,where the vegetation are well developed,are generally higher than that of the stable and semi-stable dune-tops.With the differences of the local climates,land forms(including microlandform) and vegetations,the physical-chemical properties of the aeolian sand soils above-mentioned represent the special heterogeneity.