Study on Spatiotemporal Evolution, Decoupling Characteristics and Driving Mechanism of Agricultural Carbon Emissions from Technological Progress—Panel Evidence from 21 Prefectures (States) in Sichuan Province, China

Against the dual goals of agricultural and rural carbon emission reduction, carbon sequestration and food security guarantee, this paper uses municipal panel data of 21 prefectures in Sichuan Province from 2015 to 2024 to calculate agricultural carbon emissions from multiple dimensions including farmland utilization, paddy field methane, crop cultivation, straw burning and livestock breeding. The standard deviational ellipse model (SDE) is adopted to reveal the spatiotemporal pattern of agricultural carbon emissions, and the Tapio decoupling model is applied to identify the decoupling relationship between agricultural carbon emissions and the agricultural economy. A panel model is constructed. The Breusch–Pagan Lagrange Multipkier (LM) test and Hausman test are performed to select the random-effects model to examine the impact of agricultural technological progress on agricultural carbon emissions. Robustness tests and grouped heterogeneity analysis are carried out. Furthermore, mediation and moderation models are introduced to identify the internal transmission paths and boundary conditions. The results show that: (1) From 2015 to 2024, the total agricultural carbon emissions in Sichuan Province generally declined. Animal husbandry was the primary emission source while carbon emissions from crop cultivation showed an upward trend, and carbon emission intensity kept decreasing. The spatial pattern of agricultural carbon emissions presented strong path dependence; the emission centroid remained stable in the central basin with a northeast–southwest spatial distribution. (2) The relationship between agricultural carbon emissions and the agricultural economy in Sichuan Province fluctuated alternately between strong decoupling and weak decoupling. Sustained and stable strong decoupling has not yet been achieved, and the incremental emissions from crop cultivation constitute a key factor disturbing the decoupling state. (3) Benchmark regression results indicated that agricultural technological progress significantly curbed regional agricultural carbon emissions, and urbanization also exerted emission-reduction effects. The proportion of primary industry, land scale operation and grain planting ratio significantly increased agricultural carbon emissions, whereas rural residents’ income and agricultural industrial structure showed no significant impacts. The carbon emission reduction effect of agricultural technological progress, constrained by regional endowments, presented notable regional heterogeneity. The emission reduction effect of technological progress was significant in plain and non-ethnic farming areas, while it was difficult to achieve emission reduction merely by relying on mechanization in ethnic regions and non-plain mountainous areas. (4) Mechanism tests demonstrated that fertilizer application intensity played a partial mediating role between agricultural technological progress and agricultural carbon emissions. Agricultural technological progress can indirectly reduce carbon emissions by lowering fertilizer application intensity. The multiple cropping index exerted a positive moderating effect. The higher the multiple cropping index, the stronger the inhibitory effect of agricultural technological progress on agricultural carbon emissions. This paper identified key regions, core emission reduction targets and directions for technological optimization for differentiated low-carbon agricultural governance in Sichuan Province, and provided empirical evidence for developing agriculture-specific carbon emission reduction plans tailored to local conditions. It also clarified the limits of the emission reduction effectiveness of agricultural technological advancements across different regions. The research findings can provide precise guidance for the green and low-carbon transformation of regional agriculture, assist local governments in addressing weaknesses in agricultural emission reduction efforts and mitigate risks such as rising emissions from crop cultivation and rebound effects from decoupling.