The use of additional straw in animal housing and the rapid incorporation of manure into
tillage land have been recognised as potential techniques to reduce ammonia (NH3)
emissions. However, there is the potential for these management practices to increase
nitrous oxide (N2O) emissions, i.e. ‘pollution swapping’. Emissions of N2O were monitored
during storage of either pig or cattle farmyard manure (FYM) and after application to tillage
land at two UK sites. Losses of N2O from conventionally stored pig and cattle FYM were
2.6% and 4.3% of the total-N into store, respectively. Following land spreading, N2O losses
ranged from o0.01% to 0.23% of total-N applied for stored manure, but up to 0.86% from
fresh pig FYM. There was no significant (probability P40.05) effect of extra straw use during
housing on N2O emissions following the spreading of pig and cattle FYM. No consistent
effect of FYM incorporation on N2O emissions was evident suggesting that rapid
incorporation (o4 h) can only reduce both N2O and NH3 losses under site specific
conditions. The results suggest that strategies to minimise N2O emissions from solid
manure management should focus on storage rather than land spreading, and that there is
a need to develop integrated manure management strategies to minimise ‘pollution
swapping’.