Abstract:

Based on the carbon sequestration rate method and BP neural network model, carbon sequestration status and potential of agricultural ecosystem in Fuzhou City from 2010 to 2021 were evaluated. The results showed that over the past 11 years, the average annual carbon sequestration amount of agricultural land in Fuzhou City was 203900 tons (equivalent to 747600 tons of CO₂), which grew at an average annual rate of 1.13%, with carbon sequestration of orchards occupying on nearly 70%. The contribution rate of straw returning to soil carbon sequestration of farmland (64.7%) was significantly higher than that of fertilizer application (35.3%). Spatially, Yongtai, Minhou, Fuqing and Minqing counties were the core areas of carbon sinks in Fuzhou City. Due to superior hydrothermal conditions and higher agricultural management levels in coastal regions, the carbon sequestration rate was higher than that in inland areas. Projections indicated that, under current agricultural development trends, carbon sequestration of agricultural land from 2022 to 2030 would show a fluctuating trend of first slowly decreasing and then slowly increasing. The fluctuations were chiefly driven by a slight reduction in farmland area, agriculture structural adjustments, and the delayed impact of management practice adoption. Finally, recommendations were proposed to enhance the region's agricultural carbon neutrality capacity, including strengthening the strategic role of orchard carbon sinks, promoting straw return and optimized fertilization techniques, and exploring agricultural carbon trading mechanisms.

Key words: agricultural carbon sequestration, straw returning to the field, orchard carbon sink, carbon sequestration potential, BP neural network