Effects of Different Restoration Measures on Soil Microbial Biomass Carbon and Nitrogen and Soil Enzymes in the Process of Restoration of the Desertified Grassland in Zoige
Zoige Plateau is one of the important water sources of the Yangtze and Yellow River. In the recent year, Zoige grassland had a serious desertification phenomenon due to human activities and climate changes and so on. It is considered that the complete enclosure after reseeding is good for restoration of desertified grassland. But actually reasonable grazing recovery effect is better than complete enclosure. Therefore we conducted a study on Zoige typical desertification grassland, comparative studied the effects of reasonable grazing, enclosure and natural restoration on their soil microbial biomass carbon and nitrogen, soil enzyme activities (Acidic phosphatase, Polyphenol oxidase, Peroxidase, beta-1, 4-glucosidase, beta-1, 4-N-acetyl glucosaminidase) and soil carbon and nitrogen mineralization rate. The result show that: After 6 years of restoration, compared with the enclosure and natural restoration, reasonable grazing soil microbial biomass carbon [C (101.2722.14) mg·kg~(-1)], microbial biomass nitrogen [N(67.4518.02) mg·kg~(-1)], acidic phosphatase activities [(159.036.4) mug·g~(-1)·h~(-1)], beta-1, 4-glucosidase activities [(81.1916.78) nmol·g~(-1)·h~(-1)], carbon mineralization rate [C (25.195.79) g·kg~(-1)·d~(-1)] and nitrogen mineralization rate [N (0.4760.015) mg·kg~(-1)·d~(-1)] had increased significantly. Enclosure has no significant difference with natural restoration except soil beta-1, 4-glucosidase activities [(29.9114.39) nmol·g~(-1)·h~(-1)] and nitrogen mineralization [N (0.1720.050) mg·kg~(-1)·d~(-1)] Soil nitrogen mineralization was extremely significant related to the content of microbial biomass carbon, Acidic phosphatase activities, beta-1, 4-glucosidase activities (P<0.01). Soil microbial biomass carbon and nitrogen was extremely significant correlation with Acidic phosphatase activities (P<0.01), and significant related to soil beta-1, 4-glucosidase activities (P<0.05). The result shows that during the restoration of desertification grassland, reasonable grazing is a kind of scientifically restoring measure of desertification grassland.