en is a major plant nutrient and nitrate is the form in which nitrogen arising primarily from nitrogen fertilisers leaks into water, particularly groundwater. The loss of nitrate in soil water drainage is termed leaching. Agriculture is the primary source of nitrate in groundwater. Nitrate Vulnerable Zones have been identified in order to reduce the loss of nitrogen from agricultural land.
Nitrate Vulnerable Zones (NVZ) were introduced by the Nitrates Directive and have developed in two phases since 1998. From 1 January 2009, the areas covered by Nitrate Vulnerable Zones (NVZs) were increased to approximately 70% of England. This includes the 55 per cent originally designated in 2002. Within these zones, certain agricultural practices have to be adhered to in order to minimise nitrate leaching.These measures include limiting the total amount of nitrogen that can be applied in animal manures in any one year and defining strict periods when neither commercial fertiliser nor organic manures can be applied, and defining good practice for the use of nitrogen fertilisers on farms. The primary objective is to prevent nitrate entering groundwater in order that potable supplies do not exceed the EU maximum permissible concentration of 50mgl-1 nitrate