Mineral accounting: the way to combat eutrophication and to achieve the drinking water objective

Abstract In 1998 the Netherlands government introduced a new manure policy in order to combat pollution of the environment by an excess supply of nutrients in agriculture. This policy is based on a mineral accounting system (MINAS) at the farm level and is focused more on nitrogen than in the past. MINAS came into force by an alteration of the law on fertilisers (Meststoffenwet). In MINAS chemical nitrogen fertilisers are included, because the use of these fertilisers contributes in the same order of magnitude to nitrogen surpluses as the application of animal manure. The new policy aims to alleviate the nitrogen problems caused in the period 1998–2008/2010. By implementing MINAS surface, waters will eventually be protected against eutrophication and the quality of groundwater used for drinking water will improve. Farms record all nutrient inputs and outputs accurately and report their farm surplus. A surplus exceeding the levy-free surplus is subject to a charge. The levy-free surplus will diminish in the period 1998–2008/2010. MINAS is only practicable if a balance exists between production of and demand for animal manure. Therefore the Dutch government has decided on a 20% reduction in the number of pigs in the short term.