Ammonia emissions from farmyard manure heaps and slurry stores—Effect of environmental conditions and measuring methods

Ammonia (NH3) emissions were measured from pig and cattle slurry storage by means of the funnel technique on the slurry surface and floating wind tunnels. Emissions from farmyard manure (FYM) heaps were quantified by the large open dynamic chamber technique. The trials on slurry stores were carried out in all four seasons whereas those on FYM heaps were carried out in cold temperature conditions only. Emissions from cattle slurry ranged from 1 to 1.6 g [NH3] m−2 day−1 with slurry temperatures of 4.7 and 24.3 °C, respectively, whereas emissions from pig slurry ranged from 0.8 to 2.5 g m−2 day−1 with slurry temperatures of 6.0 and 25.5 °C, respectively. FYM heaps showed average emissions of 3.4 g[NH3] m−2 day−1, with losses ranging from approximately 4.4% to 7.4% of the total Kjeldahl nitrogen (TKN) content. Emissions of ammonia from animal waste storage correlated with slurry temperature and were dependent on the measuring method used. Results obtained by the wind tunnel were considered to be the most representative of losses under real environmental conditions and could be used for an investigation of the national inventory.