Nitrate concentrations in the groundwater have been decreasing in all soil types since 2021. This decrease is due to a number of factors, including due to increased precipitation following the dry spell between 2018 and 2020. This has led to nitrates breaking down more effectively in the soil and leaching into the groundwater to a lesser degree. In 2023, average nitrate concentrations were below the European standard of 50 milligrammes per litre of groundwater. Only in the south and middle of the Sand Region was the average nitrate concentration as high as the standard . In this region 47 per cent of derogation farms showed concentrations that exceeded the standard. These facts were revealed by the report on Agricultural practices and water quality on farms registered for derogation in 2022.
Nitrogen surplus in soil decreasing
Between 2006 and 2022, farmers had begun using less nitrogen from livestock manure and inorganic fertilisers as a result of changes to fertiliser policy and their own farm management practices. This led to less nitrogen being retained in the soil, leaching into the deeper layers of the soil as nitrate alongside rainwater and ultimately ending up in the groundwater. Between 2006 and 2017 there was a decrease in this ‘nitrogen soil surplus’. Since 2018, however, there has been more fluctuation in this surplus.
If we look at the percentage of livestock manure, derogation farms applied an average of 228 kilogrammes of nitrogen per hectare in 2022. This put nitrogen use from livestock manure at the same level as 2021 and below the long-term average of 235 kilogrammes per hectare.
Monitoring of conditions for derogation
In the Netherlands, certain grassland farms are permitted to use more manure from grazing animals on their land than the amount specified in the Nitrates Directive. This is known as ‘derogation’.
This annual report by RIM and Wageningen Economic Research is one of the conditions the European Commission has established for the Netherlands. In September 2022, the European Commission decided that this exception for the Netherlands will end in 2026.
The aim of the EU (European Union ) Nitrates Directive is to protect water against pollution by excess nutrients from agricultural sources. Every four years, RIVM publishes a broader report on water quality in relation to agricultural practices in the form of the Nitrate Report. The next Nitrate Report is set to be published at the start of November 2024.