江苏省主要农作物碳足迹动态及其构成研究

江苏作为农业大省和粮食主产区,全面核算其主要农作物生产碳足迹时序动态变化与构成,可为江苏省主要作物生产体系全过程环境管理及农业绿色发展提供决策依据.本文采用生命周期评价法(LCA)核算江苏省1990—2019年水稻、小麦、玉米、大豆和油菜5种作物生产过程各环节碳排放强度,研究分析不同作物生产碳足迹时序动态变化、构成及影...

Carbon footprint dynamics and composition assessment of major crops production in Jiangsu province

Jiangsu is a major agricultural province and grain producing area.The comprehensive accounting of the temporal dynamics and composition of carbon footprint of major crops could provide decision-making basis for environmental management and green development of the agricultural sector in Jiangsu province.In this paper,Life Cycle Assessment (LCA) was used to calculate the carbon emission intensity of rice,wheat,maize,soybean and rapeseed production processes in Jiangsu province during 1990-2019,and the temporal dynamics,composition and influencing factors of carbon footprints of these crops were analyzed.The results showed that the carbon footprint per unit yield of major crops in Jiangsu province decreased but the carbon footprint per unit area increased in recent 30 years.The carbon footprint per unit yield for different crops showed as rapeseed (1.74 kg (CO₂-eq)·kg^-1)> rice (1.36 kg (CO₂-eq)·kg^-1)> wheat (0.99 kg (CO₂-eq)·kg^-1)> maize (0.81 kg (CO₂-eq)·kg^-1)> soybean (0.64 kg CO₂-eq kg^-1).For the composition of carbon footprint,CH₄ emission (54.43%) and chemical fertilizer input (20.65%) were the two major sources for rice production,while chemical fertilizer input and soil N₂O emission are the most important sources for wheat,maize,soybean and rapeseed production.Random forest analysis showed that the variation of seed,nitrogen fertilizer and agricultural machinery input were the main driving factors for the interannual change of carbon footprints for different crops.Therefore,it is necessary to take targeted emission reduction strategies for different crop production and adjust agricultural inputs and process management in order to promote the green and efficient development of agriculture.