湖北省畜禽粪便温室气体减排潜力分析

畜禽粪便是农业温室气体的重要排放源.合理的粪便管理方式可有效降低温室气体排放,同时减少环境污染.为明确不同养殖模式下适宜的粪便管理方式对温室气体减排的有效性,以湖北省为案例地,针对不同畜禽的粪便特征、区域自然条件和畜禽养殖模式等,筛选适宜的粪便管理方式;运用政府间气候变化专门委员会提出的畜禽粪便温室气体排放因子测算模型,在优化管理方式的基础上进行排放因子预测,估算由粪便管理方式改进所带来的减排潜力.结果表明,粪便管理经优化后畜禽粪便温室气体排放减少1.98~357.82 kg·头-1·a-1(以CO2当量计).根据养殖规模发展趋势预测,至2020年全省畜禽粪便优化管理所带来的减排潜力可达322.78万t(以CO2当量计).不同地区间减排效果则与当地养殖规模、养殖结构、养殖模式及适宜的畜禽粪便管理方式密切相关;畜禽种类间粪便特性的不同是其CH4和N2O减排效率迥异的主要原因;规模化养殖粪便管理方式优化是实现区域温室气体减排的重点.结合区域自然条件和畜禽养殖特征等,筛选适宜的粪便管理方式是实现区域温室气体减排的有效措施.

Mitigation potential of greenhouse gas emission in livestock manure management in Hubei Province

Livestock manure is an important agricultural source of greenhouse gas (GHG) emission. Proper management of livestock manure can mitigate GHG emission and reduce environmental pollution. To identify the effectiveness of appropriate manure management in mitigating GHG emission, the livestock manure from different breeding modes in Hubei Province were taken as a case study. The optimal manure management modes were selected according to the manure characteristics of different livestock, natural conditions and breeding modes. Using the method proposed by Intergovernmental Panel on Climate Change, the GHG emission factors for livestock manure were estimated, and the mitigation potential of GHG emission in livestock manure with adapted optimal management were evaluated. The results showed that, with optimal management mode, the mitigation potential of GHG emission ranged from 1.98 to 357.82 kg(CO₂-eq)·head^-1·a^-1. Given the development trend of the livestock in Hubei Province, GHG emission could be reduced to 3227.8×10³ t CO₂-eq in 2020 with optimal manure management. The mitigation potential of regional GHG emission was closely related to the breeding scale, structure and mode and the manure management. The different characteristics of livestock manure brought about the various reduction efficiency of CH₄ and N₂O. The key measure to reduce the regional GHG emission was to optimize the mature management for scale-feed livestock. Therefore, integration of the appropriate livestock manure management with regional natural conditions and breeding characteristics was an effective means to mitigate regional the GHG emission.