Improvement of Active Organic Carbon Distribution and Soil Quality with the Combination of Deep Tillage and No-Tillage Straw Returning Mode

During the initial period of straw return, a suitable return technology can lay foundation for long-term soil fertility improvement. This study focused on issues backward and blind fertilizer application in southern part maize-producing area Northeast Plain China. In this study, two modes (2-year no-tillage cover + 1-year deep loosening burying returning mode, NPT; 3-year rotary tillage RT), with RT mode as control, were combined different N rates (0, 192, 240 kg/ha). The changes organic carbon (SOC) its active components (MBC, DOC, LOC) 0–40 cm layer analyzed, stratification rate, pool index (CPI), SOC storages each component, maize yield calculated to evaluate short-term (3-year) differences quantity quality order find methods nitrogen rate combinations. results showed that NPT increased MBC content 20–30 layer, an increase 16.2% 37.8% 23.0% 50.3%, respectively, compared mode. Under stability was higher after addition, CPI value 10.2% 20–40 not significant (p < 0.05) between 192 kg/ha kg/ha, but did show changes. storage had highest under kg/ha. Therefore, we thought that, early stage priming effect caused by microbial activity Considering aspects affecting improving stability, it is recommended use return.