Eutrophying deposition, 1990-2017

Eutrophying deposition on a national scale in 2017

There are large regional differences in the deposition of eutrophying compounds. In particular in areas with intensive livestock farming, such as de Peel and de Gelderse Vallei, nitrogen deposition can reach levels of up to 4,000 mol per hectare respectively.
Such high deposition is mainly due to high local ammonia emissions from intensive livestock farming. Ammonia is emitted close to the ground and has a high deposition rate, so that a lot of ammonia is deposited close to the source. High emissions of nitrogen oxides (NOx) in and around the major cities in the Netherlands are responsible for higher deposition in these areas.
About 60 percent of the deposition comes from Dutch sources. The Dutch agricultural sector is the main contributor to eutrophying deposition in the Netherlands with roughly 40 percent (see also: Herkomst stikstofdepositie, 2022 (in Dutch)).

Trend

The national average nitrogen deposition, also called eutrophying deposition, was between 2,500 and 3,000 mol nitrogen per hectare in the early-1990s. This has steadily declined to current levels of about 1,600 mol nitrogen per hectare. Annual variations in meteorological conditions can, with constant emission levels, result in fluctuations in deposition of up to 10 percent.
The reduction in nitrogen deposition on the long term (1990-2017) is due to lower emissions of both nitrogen oxides and ammonia.

• The emissions of nitrogen oxides in the Netherlands have decreased by 64% since 1990. This decrease is the mainly the result of measures in traffic (including the introduction of catalysts), in industry and in the energy sector.
• The ammonia emissions in the Netherlands have also decreased by 64% since 1990. This reduction is the result of measures in the agricultural sector, such as improved feed composition, the use of low-emission animal housing, the covering of manure storages and the use of low-emission manure application techniques.
• Moreover, the foreign emissions of ammonia and especially nitrogen oxides decreased in the same period.
• The decrease in average nitrogen deposition on terrestrial ecosystems in the Netherlands has stabilised in recent years.

Across large areas of different ecosystems the deposition levels still exceed the critical loads for sustaining good ecological quality. The average degree of exceedance is particularly high in the forest and heath ecosystems (see also: Exceedance of critical loads for nitrogen deposition on nature, 1995-2016 and Environmental quality of terrestrial ecosystems: nitrogen deposition 1994–2022)
For more detailed information about the development of emissions of eutrophying substances in the Netherlands, see Emissions of National Emission Ceiling (NEC) substances, 1990-2013.