Abstract:The soil erosion is severe in the cultivation of black soil slope farmland along the slope, and the soil organic carbon content is decreasing year by year. Aiming to investigate the effects of different soil and water conservation tillage techniques on soil carbon balance in maize fields on black soil slopes, a runoff plot experiment was conducted. Conventional tillage ( CK) was used as a control, and six comprehensive management techniques for slope farmland were set up, including contour tillage (CT), ridge oriented field (RT), deep scarification tillage (ST), contour tillage + ridge oriented field (CR), contour tillage + deep scarification tillage ( CS), and ridge oriented field + deep scarification tillage (RS). The dry matter mass and carbon content of various organs of maize harvested under different soil and water conservation tillage techniques were observed, the incremental of soil carbon storage, CO2 emission carbon, and soil erosion loss carbon in maize fields were synchronously monitored, the net primary productivity (NPP) and net soil carbon income (NSCB) of maize fields were estimated. The results showed that the total carbon sequestration of maize plants was 10 201.93 kg / hm 2 ~12 357.34 kg / hm 2 , and the carbon sequestration of each organ in descending order was as follows: grain, stem sheath, leaf, ear axis, and root. The NPP of CT, RT, CR, CS, and RS treatments was significantly higher than that of CK treatment ( P < 0.05 ) , which was increased by 20.28% , 11.55% , 21.68% , 16.55% , and 7.95% , respectively. However, there was no significant difference between the NPP of ST treatment and CK treatment (P > 0.05) . Ridge oriented field, deep scarification tillage, and their combination mode would increase the total CO2 emissions of maize fields, while contour tillage and contour tillage + ridge oriented field can reduce the total CO2 emissions. The CT treatment had the highest NSCB, at 1 402.29 kg / hm 2 . The NSCB of CT, RT, CR, and CS treatments were significantly higher than those of CK treatment (P < 0.05) , while the NSCB of ST treatment were significantly lower than those of CK treatment (P < 0.05) . Overall, the contour tillage management technology model was the best, with the strongest carbon sequestration capacity. The research results can provide theoretical reference and technical support for the protection and management of sloping farmland in the black soil area of Northeast China.