2015−2020年不同省份小麦生命周期碳足迹变化分析

Analysis on Change Characteristics of Carbon Footprint of Wheat Life Cycle in Different Provinces from 2015 to 2020

基于2015−2020年14个小麦种植省份的产量、播种面积、农资投入等统计数据,计算小麦生命周期的农资投入品碳足迹,分析小麦生命周期碳足迹动态变化和不同农资投入品的碳足迹贡献,揭示小麦生命周期碳足迹变化规律及排放源,为实现农业绿色低碳发展提供理论依据。结果表明:2015−2020年14省小麦生命周期平均单位面积和平均单位产量碳足迹分别为4315.4kgCO_(2)eq×hm^(−2)和999.4kgCO_(2)eq×t^(−1),总体均呈下降趋势。北方冬(秋播)麦区的陕西和山西省、春播麦区的内蒙古和宁夏回族自治区、冬春兼播麦区(新疆)小麦生命周期平均单位面积和平均单位产量碳足迹均高于整个研究区平均值。南方冬(秋播)麦区(四川、江苏、安徽和湖北)、春播麦区的黑龙江和甘肃省、北方冬(秋播)麦区的山东和河南省小麦生命周期平均单位面积和平均单位产量碳足迹均低于整个研究区域平均值。另外,灌溉用电、化肥、柴油、种子和农药投入产生的碳足迹在小麦生命周期中平均占比分别为34.2%、51.6%、7.3%、3.7%和3.2%,表明灌溉和化肥是主要排放源。化肥是南方冬(秋播)麦区(江苏、安徽、湖北和四川)小麦生命周期碳足迹的主要排放源,四省平均占比分别为76.6%,71.3%,69.6%和70.0%,化肥减量增效是该地区的重要减排措施。灌溉用电是北方冬(秋播)麦区的河北和山西省、冬春兼播麦区(新疆)的主要排放源,其平均占比分别为45.6%、54.8%和65.2%,推广应用节水灌溉技术及研发配套低耗能农机设备是该地区的重要减排措施。由此可见,化肥减量和应用节水灌溉技术是减少研究区域小麦生命周期碳足迹的有效管理措施,结合各省农业和社会经济条件,针对性制定农田温室气体减排措施,是促进农业绿色低碳发展的关键。

In recent years,the carbon footprint of agricultural production has been a hot issue in the research on greenhouse gas(GHG)emissions reduction in China.Based on the statistical data of yield,sown area and agricultural production inputs in 14 wheat-growing provinces from 2015 to 2020,authors calculated the carbon footprint of inputs for wheat life cycle,studied the dynamic changes of carbon footprint of wheat life cycle and analyzed the proportion of carbon footprint for different agricultural inputs,and revealed the change rule of carbon footprint for wheat life cycle and the composition of emission sources.These results can provide a theoretical basis for realizing energy conservation and emission reduction in agricultural production and green low-carbon development.The results showed that the average carbon footprint per unit area and the average carbon footprint per unit yield of wheat life cycle in 14 provinces from 2015 to 2020 were 4315.4 kgCO_(2)eq×ha^(-1)and 999.4 kgCO_(2)eq×t^(-1),respectively,which showed a downward trend.The average carbon footprint per unit area and the average carbon footprint per unit yield of wheat life cycle in Shanxi province and Shaanxi province in northern winter(autumn sowing)wheat production region,the Inner Mongolia autonomous region and the Ningxia Hui autonomous region in spring wheat production region,and winter-spring wheat production area(Xinjiang)were higher than the average annual level of the total study regions in this paper.While the average carbon footprint per unit area and the average carbon footprint per unit yield of wheat life cycle in southern winter(autumn sowing)wheat production region(Sichuan,Jiangsu,Anhui and Hubei),Heilongjiang province and Gansu province in spring wheat production region and Shandong province and Henan province in northern winter(autumn sowing)wheat production region were lower than the average annual level of the total study regions of this paper.In the carbon footprint structure of wheat life cycle,the average carbon footprint of irrigation electricity,chemical fertilizer,diesel fuel,wheat seed and pesticides accounted for 34.2%,51.6%,7.3%,3.7%and 3.2%,indicating that chemical fertilizer and irrigation electricity were the main sources of agricultural carbon footprint.Chemical fertilizer was the main source of agricultural carbon footprint in Southern winter(autumn sowing)wheat production region(Jiangsu,Anhui,Hubei and Sichuan),with an average proportion of 76.6%,71.3%,69.6%and 70.0%,respectively.Therefore,reducing chemical fertilizer input and increasing utilization efficiency were important emission reduction measures in these regions.Meanwhile,irrigation electricity was the main source of agricultural carbon footprint in Hebei province and Shanxi province in northern winter(autumn sowing)wheat production region and winter-spring wheat production region(Xinjiang),with an average proportion of 45.6%,54.8%and 65.2%.Therefore,promoting the application of water-saving irrigation and developing low-energy-consuming machinery and equipment were important emission reduction measures in these regions.In short,reducing chemical fertilizer input and promoting water-saving irrigation technology to reduce the carbon footprint of wheat life cycle in study regions were effective management measures,and considering regional socio-economic and agricultural conditions of each province,formulating targeted measures to reduce agricultural greenhouse gas emissions is the key to promote the green and low-carbon development of agriculture.