Nutrient contamination of groundwater as a result of nitrogen-based fertilisers is a problem in many places in Europe. Calculations by a team of scientists led by the UFZ have shown that over a period of at least four months per year, nitrate can leach into the groundwater and surface water on about three-quarters of Europe’s agricultural land. The proportion of areas at risk from nitrate leaching is thus almost twice as large as previously assumed. How much of the nitrogen applied through fertilisation can enter the groundwater and surface water as nitrate or is denitrified (i.e. converted to molecular nitrogen and nitrogen oxides and released into the air) depends, among other things, on complex processes in the soil.
— source Helmholtz Centre for Environmental Research – UFZ | Dec 9, 2020