Ammonia emissions from UK agriculture in 1997 were estimated at 224 kt NH3-N/annum with losses from housed pig production systems accounting for around 11% of total emissions. Pig production in the UK has largely been based on slurry systems, however there has recently been a move towards straw-based systems in response to concerns over pig welfare. Studies were undertaken to quantify ammonia losses from straw and slurry based pig manure management systems, from each component of the production cycle (housing, storage, land application). Ammonia emissions were measured from pig buildings on slurry and straw-based systems, which were managed to reflect commercial stocking rates and housing conditions. At the end of the housing period, the slurry and straw-based manures were stored outside for about 7 months, and ammonia losses measured during transportation and storage. Finally, ammonia losses were measured following land application of the manures. The measurements indicated that 9 ISO of total ammonia losses from the straw-based system and 72% From the slurry based system were from housing. with land spreading accounting for <1% and 15%, respectively. The soil incorporation of slurry soon after land application was effective at reducing ammonia emissions, but had little effect on the solid manure emissions. Overall ammonia losses From the two systems were similar at around 11 kg NH3-N/500 kg liveweight gain.
