Abstract: Agricultural tillage practices significantly affect the structure and function of soil micro-bial community, as well as its control over soil carbon cycling. Conservation tillage practice based on no-tillage and crop straw returning is an important measure to improve soil carbon sequestration and fertility, in which soil microorganisms play a key role. Although many previous studies focus on the structure and function of microbial communities under conservation tillage, our overall understanding of soil microbial responses at community level upon conservation tillage is still lacking, due to the complexity of the soil, environmental factors and the different selections of microbial research methods. Furthermore, previous studies paid more attention to the role of soil microorganisms as decomposers and the contribution of plant-derived carbon to the formation of soil carbon pool, but ignored the contribution of microbial-derived carbon to the formation and stability of soil carbon pool. We summarized the paradigm shift in soil organic matter formation and stability theories, reviewed the research methods of soil microbial community, focused on the effects of conservation tillage on soil microbial biomass, community diversity and composition, carbon metabolism, as well as microbial-derived carbon storage, and proposed suggestions for future study, aiming to provide support for future studies regarding microbial responses and its control over soil carbon dynamics in agroecosystem.

Key words: conservational tillage, soil microorganism, microbial community structure, microbial carbon metabolism, soil organic carbon