Techniques and strategies for the reduction of ammonia emission from agriculture

Agricultural production systems are recognised as a major source of atmospheric ammonia (NH₃). When deposited, the NH₃ may contribute to eutrophication of oligotrophic ecosystems and to acidification. Techniques for the reduction of ammonia emission are mainly focused on reducing the NH₃ emitting area exposed to the air, reducing the NH₃ or ammonium (NH ₄ ⁺ ) concentration in solution or reducing the exchange of air above the emitting surface. In this paper we present the techniques and changes in farming practice which may reduce NH₃ emission. Due to interactions between different sources on a farm, reduction in NH₃ emission from individual parts of the livestock production system cannot simply be added to give the net reduction in emission from the total system. Thus a whole farm system approach is needed for devising control strategies for reducing NH₃ emission.