During composting, microorganisms under exothermic and aerobic conditions, transform degradable organic matter into CO2 and water. This process has several benefits to manure handling, odor control, manure moisture and pathogen control, organic matter stabilization, etc. Composting of solid manure is used as bedding in dairy production systems to reduce cost of production and provide cow comfort (Husfeldt et al., 2012). Aeration may reduce CH4 emissions, but increase N2O and NH3 emissions (Pattey et al., 2005; Webb et al., 2012). Manure can either be left undisturbed during the composting process, mechanically turned, or actively aerated. Combined CH4 and N2O emissions are generally lower after forced aeration and turning compared to passive composting (Table 4). 

Source: AnimalChange (project funded by EU - FP7)

DELIVERABLE 6.2. Deliverable title: Report on the extent to which manure management might help decrease GHG gas from animal agriculture.