生猪养殖系统碳足迹评估研究进展

Review on Carbon Footprint Assessment of Pig Farming System

【目的】畜禽养殖业是重要的温室气体排放源,我国是生猪养殖大国,科学评估生猪养殖系统碳足迹,能够为畜牧业深入推进减排降碳提供参考借鉴。【方法】本文中从碳足迹评估模型、评估方法和主要排放源三方面对国内外生猪养殖系统碳足迹评估研究现状进行梳理,围绕系统边界、排放源、核算方法以及单位选择等因素深入分析了评估结果差异性的成因,解析了饲料生产、粪污处理等环节对评估结果的影响。【结果】目前国外对生猪养殖生产全生命周期的碳足迹评估形成了较为成熟的评估模型。每生产1 kg功能单位的猪肉碳足迹为2.2—10.3 kg CO_(2)-eq。各研究中,不同评估方法会对评估结果产生较大影响。划定不同的系统边界、采用不同的功能单位,均会导致碳足迹评估结果出现差异。同时,在相同系统边界内,核算的排放源不同、同一排放源选取的参数不同,或者选择不同的分配方法也会影响评估结果。在生猪养殖生产系统中,饲料生产是对生猪生产系统碳足迹贡献最大的环节,占比为49%—83%。粪便管理环节的排放仅次于饲料生产环节,占比为12%—41%。【结论】为了使我国生猪养殖系统的碳足迹评估更加精准和广泛,应开展针对中国不同区域不同养殖模式下温室气体排放关键参数的监测,根据我国生猪养殖系统发展现状建立适合本国国情的碳足迹评估数据库,统一评估方法,规范评估要求,创建符合地区实践的评估模型,为我国生猪养殖产业的可持续发展提供数据参考。

【Objective】Livestock production is one of the important emission sources of greenhouse gases,while China is a major country in pig farming.Scientifically assessing the carbon footprint of pig farming system can provide a reference for further promoting carbon emission reduction of animal husbandry.【Method】This paper reviewed the research status of carbon footprint assessment of pig breeding system,including model,results and composition.The results of carbon footprint assessment were related to many factors,such as system boundary,emission sources,accounting methods and functional unit.In this study,we considered the main factors which affect the evaluation results,and analyzed the reasons for the difference of results.【Result】Through reviewing the domestic and foreign literature on carbon footprint assessment,it was realized that the assessment model of livestock had been constructed well in developed country.The carbon footprint of 1 kg functional unit product was 2.2-10.3 kg CO_(2)-eq.The assessment results varied due to the different evaluation methods in various studies.Different system boundaries and functional units were the important reasons for different results.The different emission sources,accounting parameters selected for the same emission source,or diverse allocation methods under the same system boundary also led to great differences.For the contribution to the carbon footprint of the pig production system,feed production was the largest link,accounting for 49%-83%;the second was manure management,accounting for 12%-41%.【Conclusion】In order to widely precise the carbon footprint of China’s pig production system,the suggestions were as follows:monitoring the key parameters of greenhouse gas emissions for various feeding modes in all regions of China should be carried out;the Chinese carbon footprint assessment database according to the development status of Chinese pig breeding systems should be established;the unified and standardized evaluation methods should be appeared publicly;an carbon footprint assessment model fit for different regions of Chinese production practice should be created to provide data reference support for the sustainable development of Chinese pig production system.