China Can Enhance Its Carbon and Nitrogen Reduction Potential by Optimizing Maize Trade Across Provinces

Interregional grain trade affects the environment while balancing supply and demand. However, what relationship exist between national carbon emissions reduction and nitrogen losses reduction in each export region is unclear. Here we used maize as a case study to address this gap by combining life cycle assessment method with linear programming model. We found that interprovincial maize trade can reduce the country’s overall carbon emissions and nitrogen losses. However, the carbon and nitrogen reduction potential varied across exporting provinces. Northeast provinces have great potential to reduce the country’s overall carbon emissions and nitrogen losses via interprovincial maize trade. Northwest provinces increase the overall carbon emissions but reduce the overall nitrogen losses when transferring out maize. Optimizing interprovincial maize trade schemes can further enhance the country’s overall carbon and nitrogen reduction potential. The research results provide a theoretical reference for China to develop carbon neutral and nitrogen reduction trade schemes. Northeast China has a high potential to reduce carbon dioxide emissions and nitrogen losses to air, water and soil via interprovincial maize trade, according to an analysis that combines agriculture and trade data with a life cycle assessment and linear optimization model.