Soil Characteristics Changes in Desertification Processes in Hunshandake Sandy Land,Northern China

Soil spatial heterogeneity is very huge in Hunshandake Sandy Land.Soil grain size on shifting dunes and soil nutrient content on non-desertified lands exist very obvious difference.With the development of land desertification,a coarse sands accumulation layer often formed in the surface of soil,and the content of soil organic carbon(SOC) and the total Nitrogen(TN) both decrease obviously.Moreover,the content of SOC has bigger spatial difference than the content of TN.With the increase of desertification severity,the content of SOC decreases much faster than the content of TN,causing the ratio of C and N decrease obviously.There are close correlation between the content of SOC,the content of TN and the clay particles content in top soil layers of desertified lands.Soil wind erosion is the main driving factor of soil developing process in land desertification,and it seriously affect the soil stability,the transfer of soil fine material composition and nutrient.