ESTIMATES OF NITROUS-OXIDE EMISSIONS FROM SOIL IN THE UK

Soil N2O emissions will be the largest single source of N2O in the UK, when industrial emissions as a result of adipic and nitric acid produ ction will stop later this year. Total annual soil N2O emissions for t he UK are estimated at 16 kt N, of which agricultural soils are respon sible for 19% of the total soil emissions and grazed grasslands (16 kt N2O-N y(-1)) are the single largest source. Deciduous and coniferous woodlands accounted for 15% and unmanaged grassland and moorlands for 16% of the total annual UK soil emission. Fertiliser N and atmospheric deposition of N are the most important variables controlling the N2O emission rate, followed by temperature and soil moisture. These three variables need to be incorporated in future more detailed estimates of regional scale soil N2O emissions.