Covering solid manure during storage with straw or a plastic sheet reduces N2O and CH4 emissions (Table 4). Yamulki (2006) reports reductions of -42 to -11% for N2O emission with straw cover on farmyard manure, and -45 to -50% for CH4 emission (comparison with uncovered manure in CO2 equivalents). However, different studies report both a reduction (-17 to -98%) and an increase (+111%) in CH4 and N2O emissions after covering poultry and cattle solid manure with a plastic sheet (Chadwick, 2005, Hansen et al., 2006, Thorman et al., 2006). Covering heap manure may also reduce ammonia emissions (Chadwick, 2005; Webb et al., 2012). 

Source: AnimalChange (project supported by EU - FP7)

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