The model Agrammon calculates ammonia loss on the basis of the N-flux (Flux Model). For the stages housing/yard, manure store, manure application, grazing and other sources the loss is calculated by using emission rates as a proportion of the soluble nitrogen in the system. For slurry stores, an emission rate per m2 of surface area of the slurry store is used. Important production variables such as feed, housing system, covering of slurry store or emission-minimising application systems are taken into account in emission rates as correction factors.