Effects of grazing exclusion on soil nutrition in moderate degraded desert grassland of Seriphidium transiliense

In order to explore the response to grazing exclusion on soil physical and chemical quality, the influences of different grazing exclusion times (including 0 year, 1 year, 4 year and 11 year) on soil organic matter, soil total nitrogen, total phosphorus, total potassium, alkali solution nitrogen, available phosphorus, available potassium, pH, soil moisture and bulk density in moderate degraded desert grasslands of Seriphidium transiliense in Xinjiang were studied by using the method of combination field survey with laboratory analysis. The results showed that the content of soil organic matter, total nitrogen, total phosphorus, available potassium substantially increased first and then decreased with the grazing exclusion times in the surface(0-5 cm). Compared with continuous grazing areas, the content of soil organic matter decreased 11.9%~23.0% in 0-5 cm of soil layer and total nitrogen decreased 17.5%~34.1% in 5-10 cm of soil layer; but the content of total phosphorus and available potassium respectively increased 8.5% and 12.0% in eleven years of grazing exclusion. In addition, the content of total potassium, alkali solution nitrogen, available phosphorus had no obvious significant. The soil moisture presented increased volatility, but soil bulk density presented decreased volatility.