吉林省半干旱区玉米生命周期碳足迹研究

Life Cycle Carbon Footprint Study of Maize in the Semi-Arid Area of Jilin Province

基于调研数据,以吉林省半干旱区玉米种植体系为研究对象,以生产1 kg玉米为评价单元,运用农业碳足迹理论及生命周期评价法研究吉林省半干旱区玉米种植系统碳足迹大小及组成,分析玉米生产过程中各种碳排放源的相对贡献。结果显示,玉米生命周期单位面积碳足迹和单位产量碳足迹分别为12.3 kg/hm^(2)和1.10 kg/kg,其中农资生产系统引起的温室气体排放对碳足迹贡献最大,占总量的52%,碳排放量为21431 kg·eq,农资生产系统中由氮肥造成的碳排放比例最高,占41%。作物生产系统对玉米生命周期碳足迹的贡献为48%,该环节的碳排放量为17257 kg·eq,其中施用氮肥产生的温室气体排放量为14209 kg·eq,占该环节碳排放总量的82.3%。各项农资投入与碳足迹的相关分析表明,玉米生命周期碳足迹主要受化肥影响,其次是耗电和柴油。建议优化煤基氮肥生产路线,研发清洁煤基氮肥技术,降低肥料生产加工过程中的碳排放量同时采取施用缓释肥料、脲酶抑制剂等方法,延缓养分释放,提高肥料利用率。

Based on survey data,this study focused on the maize planting system in the semi-arid region of Ji-lin province,using the production of 1 kg of maize as the evaluation unit,agricultural carbon footprint theory and life cycle assessment analyses were used to examine the size and composition of the carbon footprint in the maize plant-ing system,as well as to analyze the relative contributions of various carbon emission sources in the maize production process.As a result,the carbon footprints per unit area and per unit yield of maize were 12.3 kg/ha and 1.10 kg/kg,respectively.Throughout life cycle of maize,greenhouse gas emissions caused by the agricultural resource pro-duction system contributed the most(52%,21431 kg·eq)to the carbon footprint,of which nitrogen fertilizer had the largest share with 41%.Planting accounted for 48%(17257 kg:eq),and nitrogen fertilizer had a portion of 82.3%(14209 kgeq).Correlation analysis of agricultural elements and carbon footprint indicated that fertilizer is the main contributor to the carbon footprint,followed by electricity consumption and diesel.Suggestions on optimizing coal-based nitrogen fertilizer production routes and developing clean coal-based nitrogen fertilizer technologies.To re-duce the carbon emissions in the process of fertilizer production,slow-release fertilizers and urease inhibitors can be applied to delay the release of nutrients and improve the utilization rate of fertilizers.