Effect of conservation tillage on microbial community in Chinese Mollisol

Tillage systems affect soil microbial communities, which in turn influence soil ecological processes. In this study, the effects of conservation tillage (including no-tillage continuous corn and no-tillage soybean-corn rotation) on microbial community were studied by determining the contents of soil microbial biomass carbon and phospholipid fatty acids (PLFAs) and comparing it with conventional tillage continuous corn. Results show that implementation of conservation tillage significantly increases soil carbon and nitrogen, water soluble organic carbon, available nitrogen and microbial biomass C in the 0~5 cm soil depth (P<0.05) compared with conventional tillage. These conditions produce abundant substrate for microbial growth. Furthermore, conservation tillage practices increase total PLFAs, fungal and bacterial biomass in the surface layer, increase fungi/bacteria ratio, and thus improve soil sustainability. These findings are of great significance for understanding the internal mechanisms of conservation tillage.