滨海滩涂垦区主要大田作物生产碳足迹研究*——以江苏省盐城市为例

CARBON FOOTPRINT OF FIELD CROPS IN SALINE AGRICULTURE AND ITS DRIVING FORCES*——A CASE STUDY IN YANCHENG′S COASTAL AREAS

关键词:  滨海垦区大田作物生命周期法碳足迹节碳减排

Key words:  coastal area  field crops  life cycle method  carbon footprint  carbon emissions reduction

摘要:

［目的］由于自然要素组合的特殊性，与传统内陆农区相比，滩涂围垦区农业生产特点鲜明。摸清该区大田作物碳足迹，可减少区域碳排放，提升农业生产效率，优化区域资源配置。［方法］采用生命周期评价理论结合IPCC田间温室气体计算方法，建立大田作物碳足迹评估模型，估算滨海滩涂垦区大田作物温室气体排量。［结果］（1）滨海滩涂地区大田作物的碳足迹（以CO2当量）总体在063~0769kg/kg范围内，不同作物的碳足迹由大到小依次为：玉米0769±0224kg/kg、水稻0739±0241kg/kg、小麦0636±0183kg/kg和大麦0630±0184kg/kg；（2）氮肥生产和施用环节对该区碳足迹贡献度最大，贡献率分别为2646％～3712％和2906％～5194％。该地碳足迹数值和结构上呈显著地域化特点，与中国其他地区相比，氮肥施用贡献度大，水田灌溉贡献度大。［结论］降低该地区碳足迹，重点关注施氮和水稻灌溉工程两个方面。采用降低施氮量、提高氮肥利用率、发展节水农业与生态农业等措施，可达到降低碳足迹的目的。

Abstract:

Carbon emissions have always been a key issue in agricultural production. Compared with traditional agricultural zones, saline agricultural production generally has some distinctive characteristics, such as higher soil salinity, lower soil nutrients, etc. However, information derived on carbon emissions from saline agricultural production is limited. This research aims to find out the carbon footprint of field crops in the area, so as to reduce regional carbon emissions, improve agricultural production efficiency, and optimize regional resource allocation. This research established a carbon footprint assessment model for field crops by adopting the life cycle assessment theory (LCA), Intergovernmental Panel on Climate Change (IPCC), and estimated the carbon footprint (CF) of four field crop productions (barley, wheat, corn and rice) through greenhouse gas (GHG) estimation method. Furthermore, it further determined the driving forces of carbon emissions, and proposed some effective measures to reduce them. The results were showed as follows. Firstly, the CF from the four crops in the study area varied from 0.630 to 0.769 kg·kg-1, which was higher than that from traditional agriculture. Secondly, GHG emissions from Fertilizer Nitrogen (N) manufacture and inorganic N application had contributed to the greatest percentage of carbon emissions. Compared with traditional agricultural zones, fertilizer N application and paddy irrigation involved with crop productions had overall greater contributions to the CF. Carbon emissions from saline agriculture can be reduced significantly by reducing the amount of N fertilizer application, improving traditional rotation system, developing water saving agriculture and constructing ecological agriculture.