Meta-analysis demonstrating that moderate grazing can improve the soil quality across China's grassland ecosystems

Abstract

Although numerous studies have demonstrated that grazing significantly affects soil nutrients, plant biomass and soil microbial activities in grassland ecosystem, the responses of the relationships of soil nutrients with plant biomass and soil microbial activities to grazing intensities at a large scale are still unknown. Here, we conducted a meta-analysis across China's grasslands to address these questions. Our results suggested that different grazing intensities (low grazing (LG), medium grazing (MG) and high grazing (HG)) were closely related to plant biomass, soil physicochemical properties, soil microbial and enzyme activities. Specifically, MG significantly increased below-ground biomass (BGB). HG apparently decreased soil microbial activities, soil organic carbon (SOC) and total nitrogen (TN), while LG showed the opposite results. The grazing-induced changes in plant biomass, soil microbial biomass carbon and nitrogen might be the main underlying drivers that control the responses of SOC and TN to grazing intensities. The findings highlighted that LG was suitable for the sustainable development of China's grasslands and even worldwide dryland management.