Degradable organic matter in manure and other organic substrates is transformed into biogas (mainly CO2 and CH4). The process provides energy substituting fossil fuel. It reduces the potential for CH4 emissions during subsequent storage. But an enriched methanogenic microflora in digested slurry will continue to produce CH4 at high rates during the cooling phase (Sommer et al., 2000). CH4 emission must be collected to retain potential GHG mitigation. Studies show a reduction in CH4 (-32 to -68%), and in GHG emission in CO2 equivalents (-14 to -59%) from storage of digested manure compared to untreated cattle slurry (Table 6)
Source: AnimalChange (project supported by the EU-FP7)
DELIVERABLE 6.2. Deliverable title: Report on the extent to which manure management might help decrease GHG gas from animal agriculture.