Abstract:

Analyzing the carbon footprint of the rice-wheat rotation system in Jiangsu Province based on both localized and international parameters would play a key role in evaluating the carbon footprint of future agricultural ecosystem. The study objective was to analyze the typical rice-wheat rotation system in Jiangsu province. Data gathered from native farmers was used to calculate the carbon footprint of the rice and wheat growing system using both localized and international parameters, and then compared the difference between them. The results indicated the following: 1) significant differences were observed in the carbon footprint of rice-wheat rotation systems between the two calculated methods (P<0.05). The carbon footprint of the rice-wheat rotation system calculated by international parameters was 11.5% higher than that calculated by localized ones. However, the carbon footprint of wheat season did not show significant difference between two methods (P>0.05). 2) The contributions of agricultural activities to the carbon footprint varied. The carbon footprint of the rice-wheat rotation system was primarily influenced by CH₄, N₂O, and nitrogen fertilizers, accounting for 39.7%, 7.23%, and 32.6% under localized parameters, respectively, and 46.4%, 8.72%, and 27.8% under international parameters, respectively. 3) In the rice-wheat rotation system in Jiangsu Province, there is a strong correlation between the carbon footprint and the usage of nitrogen fertilizer and diesel. Furthermore, both nitrogen fertilizer and diesel showed extremely significant levels of influence (P<0.001). There was a significant negative correlation between planting scale and carbon footprint (r = −0.69). 4) Significant differences were observed in the carbon footprint of different planting scales in the rice-wheat rotation system (P<0.05). In comparison, the average carbon footprint of the wheat season was the smallest in large-scale farming, followed by medium-scale, and the largest in small-scale. In rice cultivation, the average carbon footprint was the smallest in large-scale farming, followed by small-scale, and the largest in medium-scale. In summary, the carbon footprint of the rice-wheat rotation system calculated by international emission parameters was higher compared to that calculated by localized emission parameters. The different calculation methods for CH₄ and N₂O were key factors influencing the discrepancies. Therefore, when evaluating the carbon footprint of agricultural production system in China, it is essential to select appropriate emission parameters and conduct field investigation. This would be beneficial in the establishment of an evaluation system for the carbon footprint of agricultural production systems in China and provide evidence for building a low-carbon agricultural production system.

Key words: carbon emission parameter, carbon footprint, greenhouse gas, rice-wheat rotation, life cycle assessment

摘要：

分析基于本地化参数和国际参数计算的江苏省稻麦周年轮作系统碳足迹，对评估未来农业生态系统碳足迹具有重要意义。基于农户调研数据，采用本地化参数和国际参数计算了稻季和麦季生产系统的碳足迹，并对结果进行了比较分析。结果显示，1）不同排放参数下稻季和稻麦周年轮作系统的碳足迹存在显著差异（P<0.05），国际参数下的稻麦周年轮作碳足迹比本地化参数下的稻麦周年轮作碳足迹平均高出11.5%，但小麦碳足迹在不同的参数下差异不明显（P>0.05）。2）各项农业活动对碳足迹的贡献也不同，稻麦周年轮作碳足迹主要受到CH₄、N₂O和氮肥的影响，在本地化和国际参数下分别占比39.7%、7.23%、32.6%和46.4%、8.72%、27.8%。3）江苏稻麦周年轮作系统中，碳足迹与氮肥和柴油的相关度较高，且氮肥和柴油表现为极显著水平（P<0.001），种植规模与碳足迹呈现显著负相关关系（r= −0.69）。4）在稻麦周年轮作中不同种植规模碳足迹存在显著差异（P<0.05）。通过比对发现，在小麦种植中不同排放参数下平均碳足迹都是大规模最小，中规模次之，小规模最大。而在水稻种植中不同排放参数下平均碳足迹都是大规模最小，小规模次之，中规模最大。综上，采用国际排放参数对江苏省稻麦周年轮作碳足迹计算结果会高于本地化排放参数，且CH₄和N₂O的不同核算方法是影响差异的关键因素。因此，对中国农业生产系统进行碳足迹评估时，应当选择合适的排放参数和加强实地调查，从而为中国农业生产系统碳足迹的研究制定一套统一的评价体系，为最终构建低碳农业生产体系做支撑。

关键词: 碳排放参数, 碳足迹, 温室气体, 稻麦周年轮作, 生命周期法