Soil Nutrient Characteristics Under Land Covers in Minqin Oasis-Desert Ecotone

Minqin oasis—desert ecotone,located in the northwest arid area of China,was selected to conduct a comprehensive evaluation research on the differences of soil nutrients and soil fertility under different land cover types.8transects and 221sampling points were made,including Minqin desert botanic garden,Dongba township and Suwu Mountains.Results showed that:(1)Soil organic content varied in the order of oasis areaoasis—desert ecotonedesert.Discrete degree of soil nutrient content for different transects was large as the CVchanges from 16.67%to 410.68%,as affected by human activities and desert landscape characteristics.The variation of soil nutrient with different land cover types tended to increase from desert to desert— oasis ecotone and then to oasis in the transects.(2)There were differences in the contents of soil N,P and K among grassland,shrub land,forestland and wasteland due to different human activities,soil types,soil textures and vegetation types.(3)Soil fertility quality index varied in the order of grassland(0.552) shrub land(0.057)forestland(-0.642) bare land(-0.677),which shows that grass and shrub has a good improvement effect on soil fertility.