东北是我国重要的粮食主产区,在国家粮食安全保障中起着至关重要的作用.作物生产是主要的碳排放源,探明不同作物生产的碳足迹差异,对促进低碳农业发展具有重要意义.本研究利用20042013年东北三省主要粮食作物(水稻、玉米和大豆)的产量、播种面积、农田生产投入等统计数据,估算了该区粮食生产碳足迹.结果表明: 20042013年,东北地区3种主要粮食作物中,水稻生产单位面积碳足迹最高,平均达到(246356) kg CE·hm~(-2),玉米次之.玉米的碳足迹上升趋势最明显,从2004年的1164 kg CE·hm~(-2)增加到2013年的1768 kg CE·hm~(-2),增速为67 kg CE·hm~(-2)·a~(-1).在碳足迹构成中,化肥贡献最大,分别占水稻、玉米、大豆总碳投入的45%、90%、83%.水稻生产中灌溉用电所占比例为29% ~ 42%,远高于玉米和大豆.东北三省碳足迹差异显著,3种作物的单位产量碳足迹均在吉林省最高,单位面积碳足迹均在黑龙江省最低.随着农村劳动力非农化和作物生产机械化的快速递增,未来粮食生产中柴油等机械化碳投入将快速增长.提升化肥利用效率、灌溉效率和机械化作业效率将是发展东北地区低碳农业的关键途径.
英文摘要:
Northeast China is one of the most important farming regions in China,due to its great contribution to national food security. Crop production is a main source of carbon emission. To assess the differences in carbon footprints of major grain crop production will benefit the achievement of low carbon agriculture. Therefore,this study calculated the regional carbon foot prints of rice(Oryza sativa),maize(Zea mays) and soybean(Glycine max) production in Northeast China during 2004-2013 using the provincial statistical data,including crop yield,sown area and production inputs. The results showed that the highest area-scale carbon footprint was found in rice production, with the average value of(246356) kg CE·hm~(-2),while the second was found in maize production during 2004-2013. The sharpest rise occurred in maize production,from 1164 kg CE·hm~(-2) in 2004 to 1768 kg CE·hm~(-2) in 2013,with the average rate of 67 kg CE·hm~(-2)·a~(-1). The application of chemical fertilizer contributed to the carbon footprint largely,accounting for 45%,90% and 83% for rice,maize and soybean,respectively. Moreover,the contribution of electricity for irrigation in rice production ranged from 29% to 42%,which was larger than that in maize and soybean production. The carbon footprints were significantly different among the three provinces of Northeast China. The highest yield-scaled carbon footprints for three crops were found in Jilin Province,while the lowest area-scaled carbon footprints found in Heilongjiang Province. Given to the large transfer of rural labor from agricultural to non-agricultural sections and the development of mechanization, diesel and other mechanical inputs would increase rapidly in the future. Therefore,improving fertilizer utilization,mechanical and irrigation efficiencies in crop production would be the main approaches to promoting low-carbon agriculture in Northeast China.