Influence of Land Use Types to Nutrients,Organic Carbon and Organic Nitrogen of Soil

The paper carries out field investigation on surface soil under different land use types of Shuangjiang County in Yunnan Province.The outcomes show that along with the ways of land use changing from natural forest land(for check) to shrub-grassland,economic forest and cultivated land,the natural water content and the contents of pH value,hydrolysis N,available P and available K of soil are decreased gradually,and some of them decrease remarkably(p0.05).The variation degree is cultivated land economic forest shrub-grassland natural forest land.The contents of soil organic carbon(SOC) and total nitrogen(TN) of soil are also significantly decrease(p0.05) except the SOC of shrub-grassland.In the meanwhile,the carbon density of soil decreases correspondingly.