Effects of grazing on soil microbial and biomass enzyme activities in Wugong Mountain, China

To understand the effects of different grazing intensities on soil microbial biomass carbon and nitrogen and enzyme activities in Wugong Mountain meadow, we conducted a study to provide a theoretical basis for the restoration of degraded meadow. The results showed that the contents of soil microbial biomass carbon and nitrogen in the 0-20 cm soil layer were higher than that in the 20-40 cm soil layer. In addition, with increased grazing intensity, the contents of microbial biomass carbon and nitrogen were decreased significantly (P<0.05); however, there was no significant difference in the contents of microbial biomass nitrogen (P>0.05) between light and moderate grazing in the 20-40 cm soil layer. The contents of dissolved organic carbon and nitrogen were not significantly different in the 0-20 and 20-40 cm soil layers (P>0.05). The contents of dissolved organic carbon and nitrogen with light grazing were higher than those with moderate and high grazing treatments in the 0-20 cm soil layer (P<0.05). The contents of alkaline nitrogen and readily oxidizable carbon with light grazing were significantly higher than contents with moderate and high grazing in the 0-20 and 20-40 cm soil layers (P<0.05). Soil β-glucosidase, β-N-acetylglucosaminoglycan, and urease activity were significantly higher with light and moderate grazing than with high grazing in the 0-20 and 20-40 cm soil layers (P<0.05). Correlation analysis showed that the activities of soil β-glucosidase, β-N-acetylglucosaminidase, and urease were positively correlated with microbial biomass carbon and nitrogen at all grazing intensities (P<0.05 or P<0.01).