Abstract:

To study the soil carbon sequestration potential, a long-term monitoring site of wheat and maize double-cropping farmland in Xiangcheng County, Henan Province was selected as the research object. The Century model was used to simulate the dynamic change process of soil organic carbon during the monitoring period (2010-2023), and the applicability of the Century model was verified by comparing with the measured data. At the same time, one basic agricultural management measure and four optimized agricultural management measures were selected to simulate and predict the soil carbon sequestration potential in the next 20 years (2024-2043) by using the Century model. The simulation results showed that during the monitoring period, soil organic carbon density at the monitoring sites increased by 0.31 mg/hm² annually, showing a “carbon sink” status, mainly due to the increase of nitrogen fertilizer application rate. The results of Century model validation found that the model had good applicability in simulating and predicting the dynamic change of soil organic carbon. Under the condition of basic agricultural management measures, the soil carbon sequestration potential was low, and the state was weak and stable. Under the condition of agricultural management measures combining less tillage and 50% straw returning, the soil carbon sequestration potential was the highest, which was the most effective agricultural management measure. Therefore, the implementation and popularization of optimized agricultural management measures in the wheat and maize double-cropping farmland area of Henan Province is an important means to enhance soil carbon sequestration capacity, which is of great significance for alleviating greenhouse effect and realizing national food security.

Key words: soil carbon sequestration potential, wheat and maize double cropping farmland, Century model, agricultural management practice, Xiangcheng County