畜禽粪便是农业温室气体排放的主要来源之一,合理的粪便管理方式可以降低温室气体排放,同时还能减少畜牧业环境污染。本文以湖北省为案例,通过对不同生猪养殖规模的调研,确定各自适宜的粪便处理模式。以IPCC(2006)中计算畜禽粪便温室气体排放的方法为基础,分析生猪粪便温室气体排放因子的现状和优化值,预测由粪便管理模式改进所带来的减排潜力。结果表明,在2012年的养殖规模和养殖模式不变的情况下,粪便管理优化后CH4排放因子仅为现状值的29.12%,N2O排放因子比现状减少34.13%,温室气体减排潜力可以达到468.31万t CO2-eq。不同养殖规模减排重点各有侧重,农户散养应以控制CH4排放为主,而规模养殖则需关注N2O减排。山区的减排重点为农户散养,其它地区则应关注规模养殖粪便管理模式的优化。结合区域自然条件和生猪养殖规模等选取合理的猪粪管理方式,是实现温室气体减排的有效措施。
Livestock manure is one of the main sources of agricultural greenhouse gas(GHG)emissions. Proper management of livestock manure can reduce GHG emissions and mitigate environmental pollution at the same time;however,the mitigation potential of optimal livestock manure management is not clearly stated. In order to estimate the mitigation potential of pig manure management,Hubei province in China is used as a demonstration place. Based on field surveys and natural conditions,the appropriate manure management mode for each farming scale in Hubei is chosen. The protocols for estimating GHG emission factors proposed by the Intergovernmental Panel on Climate Change(IPCC)is used to analyze current GHG emission factors and optimal scenarios for pig manure management,and then predict the mitigation potential of GHG emissions. Under optimized pig manure management,for the same farming scales and patterns in 2012,4 683 kt CO2- eq of GHG emissions could be reduced in Hubei. Meanwhile,the methane(CH4)emission factor reduced to 29.12% of the current value and the nitrous oxide(N2O)emission factor decreased 34.13% compared to current values. In order to reduce GHG emissions,manure management for scatter-fed pigs should control CH4 emissions and scale farming should focus on reducing N2 O emissions. The most effective measure to reduce GHG emissions in mountain areas in western Hubei is to adjust manure management for scatter- fed pigs and in other regions is to optimize manure management for scale farming pigs. Appropriately selected pig manure management combined with regional natural conditions and breeding scales is an effective means to mitigate agricultural GHG emissions.