Regulation of soil inorganic carbon content by the interaction between human agricultural activities and environmental factors

Introduction Soil inorganic carbon (SIC) stability improves soil erosion resistance. Clarifying the dynamic variations of SIC is crucial for optimizing climate and environmental quality in subtropical wetland agricultural areas and elucidating the carbon balance of urban forests. Methods This study was conducted in the Poyang Lake District of Nanchang City. Combining literature review and field sampling, a random forest model was constructed to predict SIC content. Correlation and difference analyses were further applied to investigate the spatial distribution and vertical patterns of SIC. Results Cultivation activities significantly increased regional SIC content by 6.56% ( p < 0.05), and a critical value existed for cultivation years, verifying that human agricultural activities are key factors affecting local SIC content. Discussion This study clarifies the influence mechanism of human activities on urban forest SIC in subtropical wetland agricultural areas, offering a theoretical basis for improving soil carbon sink capacity. Nevertheless, the findings are region-specific and cannot be universally applied to other soil types and climate zones, with certain application limitations.