Spatiotemporal Variation in Soil Nutrient of Stipa purpurea Steppe Fenced in the Qinghai Lake Region

Abstract

Soil restoration is a major aspect of ecological restoration.The study was conducted in Stipa purpurea steppe fenced for years,to detect the spatiotemporal variation of soil nutrient after fencing.The results showed that in the same plot the contents of available N,P and K in surface layer significantly higher than those in the second layer,and there were no significant differences among the lower layers.Fencing had different effects on different available nutrients: It had little effect on available K,however,the content of available P was mostly higher than that of CK,and the content of available N was a bit higher than that of CK.Fencing had little effects on the content of total K and total P,while the content of total N decreased with soil depth,and was higher than that of CK in the surface layer after fencing(increased by 19.9%).The content of soil organic matter(SOM) decreased with soil depth,and long time fencing resulted in the elevation of SOM content.Correlation analysis showed that the contents of available K and total K had no significant correlation,the contents of available P and total P,available N and total N both showed significant correlation,and SOM only showed significant correlation with total nitrogen among total nutrients.And fencing resulted in slightly elevation of pH value;Soil bulk density increased with soil depth,but no significant difference was found between fencing and CK.Fencing resulted in elevation of soil nutrient,but it was a very slow course,so the protection for Stipa purpurea steppe should be preceded.