Table 1_Carbon and nitrogen footprints of major corn production systems in China.docx

IntroductionIn the context of global climate warming and agricultural carbon emission management, corn, as the widely cultivated and cereal crop in China, plays a crucial role in ensuring food security and supporting the development of the livestock industry. Its production process generates carbon emissions and can affect the nitrogen cycle in the environment. To contribute to a more comprehensive understanding of regional characteristics and policy landscape, this study aims to calculate the carbon and nitrogen footprints of corn production in China and explore relevant emission reduction strategies, thereby providing a more comprehensive nationwide systematic analysis and offering a more nuanced depiction of regional differentiation.
MethodsThis study uses agricultural statistical data from 2014 to 2023 to analyze corn production trends. Major corn-producing regions are categorized based on government’s corn regional planning and agroecological humidity zones. This study employs life cycle assessment and area-weighted methods to estimate the carbon and nitrogen footprints across major corn-producing regions. It further examines the impact of key factors—including planting area expansion, fertilizer reduction, and pesticide reduction—on carbon and nitrogen footprints through scenario-based simulations.
ResultsThe results indicate that: (1) Both the Northwestern Irrigated Corn Region and Arid to Semi-arid Zone have elevated carbon footprints, while nitrogen footprints peak in the Northwestern Region and Arid Zone (2) Scenario simulations show that planting area expansion serves as a baseline for the carbon and nitrogen footprints. The impact of fertilizer and pesticide reduction on the carbon footprint varies depending on regional characteristics, while fertilizer reduction has a notably greater effect on reducing the nitrogen footprint.
DiscussionThis study provides quantitative evidence and policy recommendations for balancing food security with low-carbon transformation and nitrogen management in major corn-producing regions, thereby contributing to carbon neutrality and agricultural sustainability in China.