The impact of different grazing intensity on topsoil physical and chemical properties in Xilamuren grassland

摘要

Grassland is an important ecosystem in land surface. Soil is the basis of grassland ecosystem, and the changes of its properties directly affect grassland ecosystem. The study region is located in Xilamuren grassland using the methods of field sampling and experimental analysis. It was divided into four test areas according to grazing intensity. Soil physical and chemical properties were analyzed in each test area. The results showed that: the trend of soil water content decreased and then increased with increasing grazing intensity, soil water content in repaired grassland was the lowest. For the soil mechanical composition, particle size content increased first and then decreased with increasing grazing intensity when the particle size was 1-0.05mm. The difference between the highest and lowest values was obvious. When the particle size was 0.05-0.002mm, the trend of particle size fluctuated, first decreased and then increased, finally reduce again and the difference between the highest and lowest values was obvious. When the particle size was less than 0.002mm, the trend of particle size content increased with increasing grazing intensity. In soil chemical properties, soil organic matter appears downward trend overall as grazing intensity increase. Soil organic matter content was the lowest in repaired grass. Available N and P first decreased and then increased with increasing grazing intensity, the minimum values appeared in the repaired grassland and degraded grassland respectively. Available K content increased with increasing grazing intensity.