2014-2023年江苏省小麦生产体系碳氮足迹年际变化特征及构成分析OA

To provide a basis for formulating carbon and nitrogen reduction measures for wheat produc-tion in Jiangsu Province,a carbon and nitrogen accounting boundary for Jiangsu's wheat production system was constructed,analyzing the resource input characteristics and carbon and nitrogen footprint trends from 2014 to 2023,based on the life cycle assessment method.The results indicate that over the decade,the cost per unit area and per unit yield in Jiangsu's wheat production system showed an upward trend.Agricultural input costs were primarily attributed to fertilizers(33.38％-40.06％)and machinery(30.21％-35.72％).The per unit area carbon footprint and per unit yield carbon foot-print of wheat were 2.52 t·hm-2 and 0.46 t·t-1,respectively,while the per unit area nitrogen footprint and per unit yield nitrogen footprint were 103.96 kg·hm-2 and 18.89 g·kg-1.The carbon footprint generally exhibited an increasing trend over time,with an annual growth rate of 2.23％,while active nitrogen emissions showed little variation.In the carbon footprint composition,fertiliza-tion and machinery(irrigation and diesel)were the primary sources of wheat carbon emissions,con-tributing 63.70％and 22.38％to total emissions,respectively.Ammonia(NH3)volatilization was the main pathway for active nitrogen emissions in wheat production.The per unit yield carbon and ni-trogen footprints were significantly negatively correlated with wheat yield.Overall,reducing carbon emissions in wheat fertilization and mechanical operations,along with increasing straw carbon seques-tration,are key strategies for lowering wheat production carbon and nitrogen footprints.Measures such as promoting organic fertilizer substitution for chemical fertilizers,integrated water and fertilizer management,straw return,and the use of lightweight agricultural machinery can enhance fertilizer efficiency and mechanical productivity,thereby reducing carbon and nitrogen emissions in wheat pro-duction and achieving green,low-carbon,and sustainable development.