资源科学 ›› 2016, Vol. 38 ›› Issue (7): 1395-1405.doi: 10.18402/resci.2016.07.19

• • 上一篇    

低碳农业与农作物碳足迹核算研究述评

张丹(), 张卫峰()   

  1. 中国农业大学资源与环境学院,北京 100193
  • 收稿日期:2015-11-09 修回日期:2016-05-24 出版日期:2016-07-25 发布日期:2016-07-25
  • 作者简介:

    作者简介:张丹,女,山东青岛人,博士生,主要研究方向为低碳农业。E-mail:zhangdan8720@163.com

  • 基金资助:
    教育部新世纪优秀人才支持计划(2015QC097);农业部公益性行业(农业)科研专项(201203079);国家发展和改革委员会清洁发展机制项目(2013087)

Low carbon agriculture and a review of calculation methods for crop production carbon footprint accounting

ZHANG Dan(), ZHANG Weifeng()   

  1. China Agricultural University,College of Resources and Environmental Sciences,Beijing 100193,China
  • Received:2015-11-09 Revised:2016-05-24 Online:2016-07-25 Published:2016-07-25

摘要:

持续提高农业产量、提高土壤生产力、降低环境污染的低碳农业是21世纪发展的主旋律,碳足迹评价方法是支撑低碳农业技术转型、碳交易、碳标签等管理措施的基础。本研究收集了水稻、小麦、玉米3种作物的22个研究结果,发现碳足迹仍有很大的不确定性,目前国内外尚没有建立统一的碳足迹核算方法体系,导致同一作物碳足迹相差达十几倍,例如水稻碳足迹从1895 kgce/hm2(ce:CO2equal,即二氧化碳等当量),到11 811kgce/hm2,而小麦和玉米的净排放却出现相反的两个结果,即固碳(净碳排放为负值)和排放(净碳排放为正值)。分析表明,主要问题在于模型边界、温室气体种类、数据获取途径、量化单位等方面不一致,因此需要重构作物生产碳足迹研究方法。本文提出了用生命周期方法量化农作物生产碳足迹的理论模型,提出以农业投入品上游排放、农田生产排放、以及土壤固碳为边界的生命循环为边界,量化全生命链条中的CO2、CH4、N2O等直接排放因子以及NH3和NO3-等间接排放因子,通过大样本数据建立关键排放因子的量化模型,实现区域性碳足迹的定量化分析。

关键词: 低碳农业, 三大主要粮食作物, 可持续发展, 碳足迹, 生命周期评价法

Abstract:

Sustainable agriculture that increases production,improves soil productivity and reduces pollution is a hot topic in China. It is therefore necessary to evaluate carbon footprints with a Life Cycle Assessment method for low carbon agricultural practice innovation,carbon trading and carbon labels. We reviewed 22 published results for emission from rice,wheat and maize production and found that reliable approaches to quantify the carbon footprint remain vague. This has resulted in a large degree of uncertainty about the intensity of carbon footprints,even on the same crop. For example,the amount of carbon footprints of rice production ranged from 1895kgce/hm2 (ce i.e. CO2 equal)to 11 811kgce/hm2. Both positive and negative values for net emissions of wheat and maize production were obtained from previous papers. This suggests that wheat and maize production can result in carbon sequestration and carbon emissions depending on different evaluation approaches. Different system boundaries,greenhouse gas categories,approaches for data collection and units of carbon footprint could explain uncertainty. We develop a concept model to quantify carbon footprints of crop production using Life Cycle Assessment. The carbon footprint consists of three components:(1)production of agriculture inputs,such as chemical fertilizer,pesticides and so on;(2)grain production in fields;and(3)soil carbon sequestration due to grain production. The carbon emission factors include direct emission factors of CO2,CH4 and N2O and indirect emission factors of ammonia volatilization and nitrate leaching. The key emission factors were derived from big data measured at different sites and our model can quantify emissions at different scales in different regions.

Key words: low carbon agriculture, three major grain crops, sustainable development, carbon footprint, Life Cycle Assessment