Agricultural practices and water quality in the Netherlands; status (2016-2019) and trend (1992-2019)

The Nitrate rapport 2020 containing the results of monitoring effects of the EU Nitrates Directive action programmes. Over the past thirty years, the Netherlands government has taken measures to reduce nitrogen and phosphorus concentrations. This has improved the quality of ground and surface water. However water quality is not yet adequate everywhere. The nitrate concentration is too high in the upper metre of groundwater of more than half of the farms in the Sand and Loess regions. This also applies to the upper metre of groundwater in more than 30 of the approximately 200 groundwater protection areas. Also, a large part of the surface waters is not yet of the desired quality, and the concentrations of nitrogen and phosphorus are too high. After 2015, the excess of nitrogen and phosphorus increased. Since 2018 this has been reinforced by the dry summers. During drought, plants grow less well, so that they take up less nitrogen and phosphorus from the soil. Also less nitrate is broken down in the soil, which means that more leaches to ground and surface water. For example, the nitrate concentration in ditch water on farms doubled in the period 2016 to 2019. Nevertheless, the nitrate concentration in ground and surface water in this period was on average lower than in the four years before. Nitrogen and phosphorus are substances in fertilisers that farmers use to make crops grow better. An excess of nitrogen and phosphorus can leach to ground and surface water and pollute it. Nitrate is one of the forms in which nitrogen occurs in the soil and water. The improved water quality is mainly due to farmers having used increasingly less fertiliser. This reduced the excess of nitrogen and phosphorus in the soil. This also means that less nitrate leaches with rainwater to deeper layers in the soil and ends up in the groundwater. The less nitrogen and phosphorus there is in soil and groundwater, the less flows to surface water. It is important to have clean ground and surface water that can be used for the production of drinking water. Clean surface water also ensures that a larger variety of plants and animals can live in the water