Response Mechanism of Soil Microbial Characteristics to Different Land-Use Types in China

Deciphering the responses of soil properties to land-use changes is of great importance for sustainable management in biogeochemically sensitive zones. This investigation examines the impacts of agricultural conversion on soil-microbial dynamics across four land-use patterns in western Xin-jiang, China: native grassland (NG), two-year paddy field (PF), one-year corn-rice rotation field (RF), and two-year sorghum field (SF). The results indicate that different land-use types significantly altered soil properties: NG retained superior soil structure, with significantly higher porosity and organic carbon (p < 0.05). Microbial communities differed distinctly across land uses. The relative abundance of Proteobacteria ranked SF > RF > PF > NG, contrasting with Bacteroidota trends. Non-metric multidimensional scaling (NMDS) revealed divergent structures of soil microbial communities under different land-use types. The results of correlation analysis and structural equation models (SEM) showed that land use could indirectly affect bacterial diversity through its influence on soil physicochemical properties, highlighting that land-use-driven shifts in bulk density, porosity, and carbon content critically shape microbial dynamics, particularly in bacteria. These results underscore the sensitivity of soil properties to land-use practices and offer actionable insights for optimizing soil quality and sustainability in vulnerable regions.