INITIATOR is a model that calculates all major nitrogen and phosphorus fluxes in agricultural and (semi)natural ecosystems at a national and regional scale. An important part of INITIATOR calculates manure production, manure application and grazing and the use of fertilizers as well as the associated ammonia emissions in a spatially explicit way. This part of the model is used to calculate the spatial distribution of manure application and ammonia emissions for the follow-up models AERIUS, to calculate the effect on ammonia deposition, and the National Water Quality Model, to calculate the effect on water quality. These results are used for various policy-supporting activities such as the Evaluation of the Manure Act and the Emission Registration.

Integrated models are used to support and evaluate the Dutch manure and ammonia policy. These models must be maintained and adapted to the current situation, so that they can be deployed quickly if there are questions from the Ministry of Agriculture, Nature and Food Quality.