Spatio‐temporal assessment of greenhouse gas emission from rapeseed production in China by coupling nutrient flows model with LCA approach

Abstract

Abstract Rapeseed (Brassica napus L.) production experienced a considerable increase during the past decades, and there is growing concern about how to realize the dual objectives of meeting the increasing demand for rapeseed and reducing the associated greenhouse gas (GHG) emissions. Most reported studies on crop‐sourced GHG emissions to date were aimed at optimizing crop management to reduce emission, but often without a detailed spatio‐temporal assessment of GHG emissions for layout management practices. Herein, we used a newly developed modelling approach that integrates the NUtrient Flows in food chains, Environment, and Resource use (NUFER) model with a dynamic reactive nitrogen (Nr) loss module for rapeseed and Life Cycle Assessment (LCA) approach to assess the GHG emissions from rapeseed production in China, where produces 18% of the world's rapeseed. Results showed that the GHG emissions from rapeseed production in China increased by 1.90% yearly from 2004 to 2018, largely due to increased inputs of agricultural materials, especially diesel. Further, carbon footprints of rapeseed production were found vary greatly between production regions, due to diverse climatic conditions, field management practices and the level of mechanization. Scenario analysis showed that adoption of both optimized nutrient and layout management practice is required to mitigate the current resource and environmental burdens, and to achieve edible oil security. Thus, our study provides new insights for policymakers on the formulation of management practices to reduce crop‐sourced GHG emissions, going along with an increase of food demand in the future.

Keywords

• climate change
• food security
• mitigation potentials
• optimized nutrient management
• spatial adjustment