Effects of Land Use Type on Soil Salinization at Northern Slope of Tianshan Mountain

Based on field survey and laboratory analysis,the salt content of surface soils(0-20 cm) were studied in cropland,planted forest,grassland,shrubbery land,and saline alkali land of the agricultural oasis at the Sangong river catchment of Xinjiang.The result revealed that: the mean value of soil salt content was 9.33 g/kg in full agricultural oasis,and 6.9 g/kg in crop land where more than 75% soil sample was concentration in lower than 2 g/kg,but more than 10 g/kg in others land use types where soil samples were decentralization in different salinity class.Accumulation of soil salinity in different land use types was significantly affected by natural processes and human activities.Mean values of soil salinity in different geomorphology zones were increased with the change of geomorphology from south to north,and mean values was lower than 3.81 g/kg in middle-upper alluvial-proluvial delta and groundwater overflowing belt,but higher than 10 g/kg in alluvial plain.Due to different distribution pattern and utilization of southern and northern water resources,soil salinity had a moderate or great variability.