Toward Low-Carbon Rice Production in China: Historical Changes, Driving Factors, and Mitigation Potential

Area of Science:

• Agricultural Science
• Environmental Science
• Climate Change Research

Background:

• Achieving low-carbon agriculture is crucial for meeting
• Double Carbon
• targets, necessitating detailed understanding of agricultural greenhouse gas (GHG) emissions.
• Fine-scale, systematic evaluations of GHG emissions are lacking, hindering localized mitigation strategies in crop production.

Purpose of the Study:

• To analyze the county-level carbon footprint (CF) of China's rice production from 2007 to 2018.
• To identify key factors driving spatiotemporal variations in rice production's CF.
• To evaluate the potential of various strategies for mitigating GHG emissions and enhancing rice yield.

Main Methods:

• Coupling of life cycle assessment (LCA) with the DNDC (DeNitrification-DeComposition) model for county-level analysis.
• Analysis of farm-based carbon footprint (FCF) and product-based carbon footprint (PCF) from 2007 to 2018.
• Scenario analysis to assess the impact of optimized irrigation, straw-based biogas, and other agricultural practices on GHG emissions and yield.

Main Results:

• Average farm-based CF (FCF) increased significantly by 74.3 kg CO2-eq ha-1 annually, while product-based CF (PCF) remained stable.
• Considerable county-level variations in FCF (2324–20,768 kg CO2-eq ha-1) and PCF (0.36–3.81 kg CO2-eq kg-1) were observed in 2018.
• Field CH4 emissions, diesel consumption, and soil organic carbon sequestration were primary drivers of FCF heterogeneity.

Conclusions:

• Optimized irrigation and straw-based biogas production offer substantial GHG emission reductions (48.5% and 18.0%, respectively).
• Integrated strategies, including advanced crop management and fertilization, can achieve up to 76.7% emission reduction while increasing yield by 11.8%.
• County-level insights are vital for developing targeted GHG mitigation policies in rice production to support carbon-neutral agriculture.