Ammonia (NH3) emission inventories are required for modelling atmospheric N
H, transport and estimating downwind deposition, A recent inventory for UK
agriculture, estimating emission as 197 kt NH3-N yr(-1) was constructed usi
ng 1993 statistical and census data for the UK, this paper describes the de
rivation of the UK-based emission factors used in the calculation of that e
mission for a range of livestock classes, farm practices and fertiliser app
lications to agricultural land. Some emission factors have been updated whe
re more recent information has become available. Some of the largest emissi
on factors derived for each farming practice include 16.9 g NH3-N dairy cow
(-1) d(-1) for grazing, 148.8 g NH3-N liveweight unit(-1) yr(-1) for housed
broilers and 4.8 g NH3-N m(-2) d(-1) for storage of solid pig and poultry
waste as manure heaps. Emissions for land spreading of all livestock waste
were 59% of the total ammoniacal nitrogen (TAN) applied as a high dry matte
r content slurry and 76% of TAN applied as farm yard manure. An updated est
imate of emission from UK agriculture, using updated emission factors toget
her with 1997 statistical and census data, is presented, giving a total of
226 kt NH,-N per pear. (C) 2000 Elsevier Science Ltd. All rights reserved.