Spatial variation of coupling coordination degree of resource-carbon-pollution in Chinese provincial rice cropping in 2020 and related driving forces

The coupling coordination of resource utilization, carbon emissions, and pollution discharge is essential for sustainable crop production, yet remains quantitatively understudied. To bridge this gap, this study developed a coupling coordination degree (CCD) model combining carbon footprint and emergy analysis. Applied to China's provincial rice production in 2020, the framework reveals key spatial patterns: (1) Unit product carbon footprint is higher in multi-season southern provinces (10.00–34.05 kg CO2-eq/kg) than in single-season regions, mainly driven by CH4 from paddy fields. (2) Emergy inputs rely heavily on purchased non-renewable resources (e.g., services, diesel, fertilizers), and emergy sustainability indices below 1 indicate systemic unsustainability. (3) Pollution impact intensity is highest in South China (1.54–3.17 × 1011 sej/kg), linked to TN/TP in wastewater and ammonia volatilization. (4) CCD shows clear spatial divergence: most northern provinces (excluding Shandong and Henan) achieve coordination (0.74–0.99), while southern ones (except Yunnan and Sichuan) face incoordination (0.20–0.64), largely due to low resource efficiency. These findings support tailored policies for lowering carbon and pollution intensities and improving resource use. The study provides a novel spatially explicit CCD analysis to inform regional management and offers a transferable tool for optimizing resource use and reducing emissions in global crop systems.