An outlook for a national integrated nitrogen policy

Reactive nitrogen in the environment is a current and future major policy issue. Nitrogen pollution and its emissions are difficult to control, because they are associated with two of the most important human needs i.e. food and energy. In the Netherlands, several measures have been taken to decrease emissions with varying success. So far policy has been focussed on individual environmental issues related to specific sources. This paper summarises the results of a study to analyse the nitrogen problem in the Netherlands in an integrated way All relevant aspects are taken into account simultaneously. This was done by deriving regional agricultural nitrogen production ceilings, including all relevant nitrogen flows in agriculture and most relevant effects, i.e. protection of ground and surface water from nitrate pollution and N-eutrophication, controlling NH3 volatilisation in view of impacts on terrestrial ecosystems and reducing NOx and N2O emissions in view of climate change policies. For agriculture, nitrogen ceilings provide a good basis for regulating nitrogen through fertiliser use and feed import. Results show that reactive nitrogen production in the Netherlands should be decreased by 50–70% in order to reach the ceilings necessary to protect the environment against nitrogen pollution from agriculture.