Gaseous emissions from outdoor concrete yards used by livestock

Measurements of ammonia (NH3), nitrous oxide (N2O) and methane (CH4) were made from 11 outdoor concrete yards used by livestock. Measurements of NH3 emission were made using the equilibrium concentration technique while closed chambers were used to measure N2O and CH4 emissions. Outdoor yards used by livestock proved to be an important source of NH3 emission. Greatest emission rates were measured from dairy cow feeding yards, with a mean of 690 mg NH3-N m−2 h−1. Smaller emission rates were measured from sheep handling areas, dairy cow collecting yards, beef feeding yards and a pig loading area, with respective mean emission rates of 440, 280, 220 and 140 mg NH3-N m−2 h−1. Emission rates of N2O and CH4 were much smaller and for CH4, in particular, emission rates were influenced greatly by the presence or absence of dung on the measurement area.