Determining the origin of nitrogen deposition in nature areas

Nitrogen policy in the Netherlands has a long history. Since the 70’s of the last century, various measures have been implemented in an attempt to reduce emissions of different nitrogen compounds. A few examples of a wide range of measures implemented since then are the introduction of catalytic converters removing nitrogen oxides from fossil fuel burning, shallow injection of manure into the soil reducing ammonia emissions to air and lowering of the manure application rates. In 2019, the European High Court judged that the Dutch nitrogen policy with respect to nitrogen deposition onto protected nature areas was not in accordance with the European Habitats Directive. All infrastructural developments came to a halt: building houses, roads, etc. stopped. With a new Minister on Nitrogen in place since 2021, the focus became a drastic reduction of nitrogen emissions to get the nitrogen deposition below the nitrogen critical loads for 74% of the protected (Natura 2000) nature areas, which is laid down in a nitrogen law. This requires a drastic change in activities in and around these nature areas, mainly (but not exclusively) focusing on the agricultural sector. This because the contribution to the total nitrogen deposition of this sector is on average 50% in the Netherlands. To help policymakers take measures as efficiently as possible, RIVM has developed a tool that maps the origin of the nitrogen deposition in each nature area. In this presentation, the tool will be presented and it will be shown how the tool can help the government, provinces and other stakeholders to take dedicated regional measures to reduce the nitrogen emissions and eventually reduce the nitrogen deposition in nature areas.