A new inventory of ammonia emissions from Irish agriculture

Agriculture plays a vital role in the Irish economy, accounting for 3.5% of the gross domestic product (GDP) in 2000. Grassland farming and, in particular, cattle rearing and dairying accounts for more than 90% of farming activity. In addition, there have been significant increases in the number of sheep, pigs and poultry over the last twenty years. As a consequence, gaseous nitrogen (N) emissions have shown a clear upward trend. Following the adoption of the United Nations Economic Commission for Europe (UNECE) Gothenburg protocol (Protocol to the 1979 convention on long-range transboundary air pollution to abate acidification, eutrophication and ground-level ozone. United Nations Economic Commissions for Europe (UNECE), Geneva.), Ireland has to achieve a 9% reduction in national ammonia (NH₃) emissions between 1990 and 2010. The agricultural sector accounts for virtually all NH₃ emissions in Ireland. It is on this basis that a new inventory of NH₃ emissions from agriculture has been produced. This paper describes the adoption of the UK national inventory model to Irish agricultural systems, the results of model calculations and the measures available to enable compliance with national targets and areas within the inventory, which require further investigation. Estimated total emissions from Irish agriculture were 89.9 and 91.8kt NH₃-N for 1991 and 2010, respectively. Cattle farming accounts for more than 75% of total emissions. The largest emission factors found included 46.9g NH₃-Nlu^-1d^-1 for cattle housing, 29.5g NH₃-Nlu^-1d^-1 for pig housing and 150g NH₃-Nlu^-1d^-1 for housed broilers (lu being equivalent to 500kg live weight). In addition, model predictions for the year 2010 showed that without any abatement strategies being implemented, NH₃ emissions would exceed the agreed national emission reduction target by 12%. It was also found that strategies for reducing emissions from the land spreading of manure offer the greatest potential to achieve target levels.