Nitrogen deposition, 1990-2025

Decreasing trend of deposition

The national average nitrogen deposition in 1990 was over 2,700 mol N/ha. Since then, nitrogen deposition has decreased by 48%. Nitrogen deposition was 1,140 mol N/ha in 2024. Dry deposition accounts for the largest share of nitrogen deposition, while smaller amount is deposited through wet deposition.

Deposition levels can vary from year to year. Due to changes in especially ammonia emissions there are periods in which nitrogen deposition decreases only slightly. Meteorological conditions also cause annual fluctuations in deposition of approximately 10%. Another factor is improved air quality, which reduced the formation of particulate matter from ammonia (see also Relatie ontwikkelingen emissies en luchtkwaliteit, in Dutch). As a result, deposition from ammonia not always follows the same trend as ammonia emissions. Based on a provisional figure, nitrogen deposition decreased in 2025 compared with 2024.

Lower emissions caused decreasing trend

The decrease in nitrogen deposition from 1990 to 2024 is the result of lower emissions of both nitrogen oxides (NO_x) and ammonia (NH₃) (see the website of Emissieregistratie (in Dutch) (Overzichtstabellen Lucht):

• Emissions of nitrogen oxides in the Netherlands have dropped by 62% since 1990. As a result of measures such as catalytic converters, stricter emission requirements for cars and trucks, better insulation and boilers in homes and buildings, and using less coal for energy production. 
• Ammonia emissions in the Netherlands have decreased by 67% since 1990. This decrease in emissions is due to measures in agriculture. De largest decrease in ammonia emissions took place in the period before 2010 due to immediately incorporating manure into the soil when applied. Other measures, such as improving feed composition, using low-emission housing systems, and decreasing number of livestock also reduced emissions. 
• Emissions of other countries for ammonia and especially for nitrogen oxides have also decreased during the same period.
  
  

The extent to which critical loads are exceeded in Natura 2000 areas can be found at Overschrijding van kritische depositiewaarde (in Dutch). For a variety of ecosystems the deposition rates exceed the critical loads necessary for maintaining environmental quality: Environmental quality of terrestrial ecosystems: nitrogen deposition.

National patterns of nitrogen deposition

In the Netherlands there are large regional differences in the deposition of nitrogen compounds. In particular in areas with intensive livestock farming, such as the Gelderse Vallei and the Peel, nitrogen deposition can reach levels of more than 3,500 mol N/ha. This is due to the high local ammonia emissions from intensive livestock farming. Ammonia is emitted close to the ground and is deposited relatively quickly, therefore ammonia tends to be deposited closer to the source than nitrogen oxides. However, this does not mean that ammonia mostly deposits locally. On the contrary, most ammonia is deposited over a larger area of tens to several hundreds of kilometres from the source. The roughness of the terrain plays an important role here. Areas with a greater terrain roughness (for example, a forest or a city) capture more nitrogen than a smooth terrain, influencing the dispersion of ammonia over long distances.

About two-thirds of the nitrogen deposition originates from Dutch emission sources. Dutch agriculture contributes about half and is the largest source of nitrogen deposition in the Netherlands. See also: Herkomst stikstofdepositie (in Dutch).