STUDY ON THE MECHANISM ABOUT THE RESPONSE OF HUMUS CARBON TO ORGANIC MATERIAL ADDITION IN BLACK SOIL

The effects of six straw returning methods (CK, straw removal; SD, chopped maize straw returned directly; NT, straw mulch and no-tillage ; BC, biochar produced by maize straw; SDBC, chopped maize straw returned directly combined biochar; NTBC, straw mulch and no-tillage combined biochar) to humus accumulation and composition in soil (0-10cm and 10-20cm) were studied. The changes in the microbial structural composition and diversity, enzymes activities, as well as abundance of enzyme encoding gene involved in the carbon transformation, were investigated. The key factors that affect the stability of soil organic carbon pool and the microbial mechanism were analysed.