Spatiotemporal Evolution, Spatial Heterogeneity and Driving Mechanisms of Agricultural Carbon Emissions in the Main Grain-Producing Areas of the Middle Reaches of the Yangtze River, China

Abstract

Achieving low-carbon agriculture in major grain-producing areas hinges on balancing emission reduction imperatives with the need to maintain food security. However, previous studies have largely examined agricultural carbon emissions (ACE) at administrative scales, potentially overlooking heterogeneous agricultural functions and emission pathways within urban agglomerations. This study integrates ACE accounting, spatial inequality and autocorrelation analyses, and Logarithmic Mean Divisia Index (LMDI) decomposition to investigate the spatiotemporal dynamics, spatial differentiation, and driving mechanisms of ACE in the Main Grain-Producing Areas of the Middle Reaches of the Yangtze River, China, using panel data from 31 prefecture-level cities during 2013–2023. The results show that ACE experienced expansion, decline, and subsequent stabilization, while agricultural carbon intensity decreased by 37.29%, indicating gradual decoupling between agricultural development and carbon emissions. Significant spatial heterogeneity and positive spatial dependence were observed, with intra-agglomeration disparities contributing more to overall inequality than inter-agglomeration differences. The three urban agglomerations also exhibited distinct emission characteristics associated with their agricultural functions and emission structures. LMDI decomposition showed that agricultural economic development was the main factor increasing ACE, whereas improvements in production efficiency and changes in rural population mitigated emissions. Overall, the results reveal that similar regional emission trends can arise from heterogeneous agricultural functions, emission structures, and development trajectories. This highlights the need for differentiated low-carbon transition pathways rather than uniform emission-reduction strategies and provides a basis for coordinating food security with low-carbon agricultural development.