The emission rates tell us what proportion of nitrogen
is released into the air as ammonia. As ammonia emissions from animal husbandry, manure storage and manure application originate to a large extent from soluble nitrogen, emission rates are given as a percent of the amount of soluble nitrogen (% TAN; Total Ammoniacal Nitrogen).
Furthermore, a certain amount of nitrogen applied as mineral or recycling fertilizer is also lost as ammonia. The emission rate is expressed as a percent of the amount of applied total nitrogen or soluble nitrogen. Finally, processes in plants and soil also result in ammonia emissions. The emission rate used is kg of ammoniacal nitrogen per ha of agricultural land.
The emission rates used in the model are outlined under Technical Description.