Taking samples from ditch-water near farms to measure nitrate levels

The 2020 Nitrate Report

RIVM (the National Institute for Public Health and the Environment) published the 2020 Nitrate Report in November. That report gives an overview of the developments in fertiliser policy, changes in agricultural practices and their effects on the quality of groundwater and surface waters. This report is an obligation under the European Nitrates Directive. This web page gives information about how the 2020 Nitrate Report was produced, its findings and access to further information.

The Nitrate Report in brief

Watch the animated film to get a clear picture of the Nitrate Report in just over two minutes.

Crops need nutrients such as nitrogen and phosphorus.
Nutrients that they don’t take up are retained in the soil.
Or they end up in the groundwater and surface waters.
If this happens too much, biodiversity is reduced, blue-green algae affect swimming areas and too much nitrate (a highly soluble form of nitrogen) makes the groundwater and surface water less easy to use as drinking water.
The European Nitrates Directive aims to prevent this by getting all EU member states to create policies for reducing nitrogen and phosphorus emissions from agriculture into groundwater and surface waters.
The groundwater and surface water quality are measured every year in the Netherlands and a Nitrate Report is sent to the European Commission every four years to keep them up to date.
The quality of regional and national waters in the Netherlands has been improving since the early 1990s.
There are concerns, though, as nitrate concentrations in groundwater and in ditches near farms have been increasing over recent years.
The recent dry summers are the key cause of this.
There are three reasons why.
Plants grow less well, which means that they take up less nitrate.
On top of that, bacteria normally break down some of the nitrate in the ground, but they are less active in dry conditions.
The final reason why nitrate concentrations are rising is that drought means there is less water to leach the nitrate away.
The risk of droughts and other extreme weather conditions is increasing, which may mean in future that it will be even harder to achieve the water quality targets.
Policymakers will use the findings from the Nitrate Report when defining new fertiliser policy and so the Nitrate Report is helping maintain the quality of our drinking water, groundwater and surface waters.

What is the Nitrate Report?

The Nitrate Report is how the Netherlands reports to the European Union about the quality of groundwater and surface water in the country. This is done once every four years, in the context of EU European Union (European Union) legislation for protecting the natural and living environment.

The report states how groundwater and surface water quality has evolved over time and its relationship to developments in agricultural practices. Although the name might make you think otherwise, it is not only about the quantities of nitrate in the water but also about the total quantities of the nutrients nitrogen and phosphorus.

The ministries of Agriculture, Nature & Food Quality (LNV) and Infrastructure and Water Management (I&W) use the report to develop a Nitrate Action Programme for the Netherlands every four years. Its purpose is to prevent water becoming contaminated by nutrients from agriculture and to reduce contamination where necessary. For that reason, the Nitrate Report also contains a prognosis of the water quality that will be achieved by the current Nitrate Action Programme (2018-2021), the sixth.

RIVM produces the Nitrate Report together with Statistics Netherlands (CBS), Rijkswaterstaat (the Directorate-General for Public Works and Water Management)/Water Traffic and Environment (RWS/WVL), Deltares, Wageningen Economic Research and the Netherlands Enterprise Agency (RVO). RIVM carries out part of this study, coordinates the production of the report and sends it to the EU and the ministries.

The Nitrate report is meant for the European Commission and Dutch Ministries of Agriculture and Economy

What are nitrogen and nitrate?

Both artificial fertilisers and animal manure contain nitrogen and phosphorus. Those are nutrients that plants need if they are to be able to grow. Any surplus of nitrogen or phosphorus can leach away into the groundwater and surface water, thus polluting it. Nitrate is one of the forms in which nitrogen occurs in soil and water.

Explanation how nitrogen and nitrate arise from cattle

Consequences for water quality and biodiversity

Excessive amounts of nutrients in the water have negative effects on the water quality in the Netherlands in various ways. First of all, there can be too much growth of blue-green algae in swimming areas. Contact with or ingestion of blue-green algae can cause health issues. Animals that drink the water can also show symptoms of toxicity.

Another negative effect is biodiversity reduction because only a limited number of flora and fauna species benefit from the greater availability of nutrients; rarer species in particular do not benefit. As a result, the number of species declines.

On top of that, it is easier for drinking water companies to supply clean drinking water if there is already less nitrate in the groundwater and surface water to start with. Too much nitrate in the drinking water is unhealthy.

Conclusions of the 2020 Nitrate Report

  • Nitrogen and phosphorus concentrations have decreased strongly over the last thirty years. As a result, groundwater and surface water quality has improved.
  • The water quality improvement is primarily because farmers started using less fertiliser and the surpluses of nitrogen and phosphorus in the soil decreased as a consequence.
  • However, the water quality is not yet sufficient everywhere: in the uppermost metre of the groundwater at more than half of all farms in the Sand and Loess Regions, the nitrate concentrations are too high according to the EU European Union (European Union) standard of 50 mg/l. This also applies to the uppermost metre of the groundwater in over thirty of the roughly 200 groundwater protection areas.
  • There is also a large proportion of surface water bodies that do not yet comply with the desired quality levels according to the standards of the Water Framework Directive: the concentrations of nitrogen and phosphorous there are too high.
  • Surpluses of nitrogen and phosphorus in the soil increased after 2015. Nitrate concentrations in the water on farms increased again after 2016. This effect was exacerbated from 2018 onwards by dry summers. Nevertheless, nitrate concentrations in groundwater and surface waters were lower on average for the period 2016-2019 than in the previous four years.
Watersamples taken from ditch-water near farms to measure nitrate levels in surface water

Would you like to know more?

The 2020 Nitrate Report

More information

  • Agriculture-Specific Waters Monitoring Network (deltares.nl) (in Dutch)
  • Water Framework Directive – KRW NUTrend (krw-nutrend.nl) (in Dutch)

Foto 1

Samples are taken from ground water in rural area for nitrate measurement.

Foto 2

Ditch running through farmland in rural area