中国农作物碳足迹核算研究概述

REVIEW ON RESRARCH OF CROP CARBON FOOTPRINT ACCOUNTING IN CHINA

关键词:  农作物碳足迹  核算  系统边界  构成  时空分布

Key words:  crop carbon footprint  account  system boundary  constitution  temporal and spatial distribution

摘要:

目的 碳足迹核算是对农业温室气体排放的定量评价，开展农作物碳足迹核算理论研究能够为低碳农业建设提供技术支撑。方法 文章在对我国农资投入变化情况进行简要分析的基础上，从碳足迹概念，碳足迹核算的数据来源、方法，我国农作物碳足迹核算涉及的对象、系统边界以及构成、时空分布特征等方面，系统总结了当前农作物碳足迹核算的研究进展。结果 （1）目前我国已开展碳足迹核算的农作物主要有水稻、玉米、小麦、大豆、油菜、脐橙、苹果、油菜和烟叶等，研究过程中活动水平数据、温室气体排放参数来源和核算包含过程的不尽相同，核算过程有仅针对研究对象生产环节的，也有包含上游环节和生产环节的，部分研究还包括产品加工、运输分销、消费和废弃环节，因此核算结果差异较大。（2）研究表明，肥料尤其是氮肥的施用和灌溉耗电是小麦和玉米生产温室气体排放的主要来源，稻田CH₄排放是水稻最主要的排放源，肥料施用和施肥后田间N₂O排放是棉花、花生、大豆、油菜和水果等的温室气体排放的主要来源。（3）同时，受农资投入、耕作方式和技术手段等影响，农作物的碳足迹是不断变化的。结论 农作物碳足迹核算研究需要全面考虑作物生产的全生命周期，采用本地化的温室气体排放参数，建立符合当地实际的碳足迹核算模型，为低碳农业的发展提供科学支撑。

Abstract:

Carbon footprint accounting theory is a quantitative evaluation of agricultural greenhouse gas emissions, and the research on crop carbon footprint accounting could provide technical support for the theoretical construction of low-carbon agriculture. Based on the brief analysis of the changes of agricultural inputs in China, this paper systematically summarized the current research progress of crop carbon footprint from four aspects: the concept of carbon footprint, the data sources and methods of carbon footprint accounting, the objects, system boundary, composition of crop carbon footprint accounting in China, and the characteristics of temporal and spatial distribution. The results were showed as follows. (1) At present, the crops that had carried out carbon footprint accounting in China mainly included rice, corn, wheat, soybean, rape, navel orange, apple, rape, tobacco leaf, etc. And during the research process, the activity level data, sources of greenhouse gas emission parameters, and the accounting process were different. In addition, the accounting processes included only the production stage, or upstream stage and production stage, and some studies also included product processing, transportation and distribution, consumption and waste stage, so these made a significant difference in accounting results. (2) The accounting results showed that, fertilizer, especially nitrogen fertilizer, and irrigation power consumption were the main sources of greenhouse gas emissions from wheat and corn production; CH₄ emission from paddy field was the main emission source of rice; N₂O emission in the field after fertilizer application and fertilization were the main source of greenhouse gas emission from cotton, peanut, soybean, rape and fruit. (3) In addition, the carbon footprint of crops was constantly changing due to the impact of agricultural inputs, farming methods and technical means. Therefore, the research on crop carbon footprint accounting needs to consider the whole life cycle process of crop production comprehensively, use localized greenhouse gas emission parameters, establish a carbon footprint accounting model in line with local reality to evaluate the composition and temporal and spatial distribution characteristics of crop carbon footprint, so as to provide scientific support for the development of low-carbon agriculture.