Spatiotemporal dynamics of crop residue utilization drive regional carbon mitigation in China

To achieve China's goals of peaking carbon emissions and achieving carbon neutrality, carbon sequestration and mitigation in agriculture and rural areas are crucial measures with significant potential. The comprehensive use of crop residue (CR) is vital in carbon sequestration and mitigation in agriculture and rural areas. This study analyzed the spatiotemporal variations in CR yields and carbon dioxide (CO₂) mitigation from the comprehensive utilization of CR in Sichuan Province, a central agricultural province in southwest China. The results are as follows: 1. Over the past 30 years, CR yields have shown a slight growth, with rapid increases in maize and rapeseed sown areas being the main driving factors. 2. From 2015 to 2022, the average utilization capacities of CR as fertilizer, feed, and energy can be described by replacing all K₂O, 58.29% of P₂O₅, and 31.85% of N in fertilizers, feeding 15.76 million sheep units (SU), and replacing 2.33 Mt of standard coal per year, respectively. Importantly, CO₂ mitigation from CR comprehensive utilization was up to 8.40 Mt per year, of which energy utilization contributed the most. 3. Combined with CR yields and comprehensive utilization status, CO₂ mitigation areas are mainly distributed in the Chengdu Plain, northeast and southern Sichuan.