Nutrienten in bodem en grondwater: Kwaliteitsdoelstellingen en kwaliteit 1984-2000

This report is one of the background reports of the evaluation report "MINAS en Milieu" It deals with the impact of fertiliser- and manure application in agriculture on the quality of soil (phosphrus) en groundwater (phosphorus/nitrogen). It is based on monitoring data carried out in the period 1984-2000. The report describes the actual status of quality standards with respect to nutrients. The agricultural soils in the Netherlands are in general phosphorus-rich. Nitrate concentrations in groundwater are high in shallow groundwater (in 2000 in sandy areas ca 125 mg/l: more than twice the standard value) but show a decrease since 1995, due to lower N-surpluses in dairy farming. At greater depths, concentrations are lower due to a combination of slow travel time, hydrology and decay (denitrification). In certain areas the abstracted groundwater for public water supply shows an increase of co-products of denitrifiaction e.g. sulphate, metals (nickel) and hardness