Abstract: The CENTURY model was used to simulate maize yield and soil organic carbon content in Northeast China from 2000 to 2020 under different farmland management practices. The objectives were to identify the key factors affecting maize production in Northeast China and to evaluate the effects of changes in farmland management practices on maize yield and soil carbon sequestration. The results showed a trade-off relationship between maize yield and soil carbon sequestration under different tillage methods. Deep plowing combined with mechanical tillage effectively increased maize yield in the short term but was detrimental to long-term stable production. The positive effects of increasing fertilizer application on yield improvement and soil carbon sequestration became non-significant after 20 years. Straw return required continuous implementation for more than 10 years to exert a significant impact on the soil carbon pool. Increasing irrigation volume promoted maize production and soil carbon sequestration capacity to a certain extent. From 2000 to 2020, the adoption of reduced tillage increased soil carbon sequestration by 2 922 g/m² and resulted in a maize yield increase of more than 10% compared with deep plowing combined with mechanical tillage. A 25% reduction in fertilizer application was more conducive to the stability of farmland system productivity.

Key words: model simulation, farmland management practices, maize yield, soil organic carbon, assessment, Northeast China