Effects of utilization modes on soil physical and chemical properties of springautumn grassland in the Xinyuan county

The mowing grass, normal grazing, sectional grazing and rotational grazing were indentified to utilize the springautumn grassland in Zeketai town, Xinyuan County. A field investigation was conducted to determine effects of four utilization modes on the soil physical and chemical properties of the springautumn grassland. The results of this study showed that soil sand particle content with the average value of 21.23% was highest, and silt particle content was the lowest under the normal grazing. At 10-20 cm layer, the silt particle content of normal grazing was significantly lower than that of rotational grazing (P0.05). The utilization modes did not affect the soil bulk density, which was 1.08-1.26 gcm-3. The soil organic matter, available N and OlsenP contents at grazing unitization modes were higher than those at mowing grass. The organic matter contents of normal grazing and rotational grazing were higher than that of sectional grazing. The available N of soil surface at normal grazing was significantly higher and the available K and OlsenP contents were lower than those at sectional grazing and rotational grazing. Therefore, the rotational grazing and the sectional grazing were better utilization modes than normal grazing because they maintained high soil nutrient. However, compared with rotational grazing, the sectional grazing increased the surface soil sand content and bulk density and decreased the organic matter content. This study suggested that it is necessary to reduce the use intensity when the sectional grazing was applied.