AGRICULTURAL NUTRIENT LOSSES TO SURFACE-WATER IN THE NETHERLANDS - IMPACT, STRATEGIES, AND PERSPECTIVES

Nutrient emissions from agricultural activities have become the domina nt source of nutrient loads to freshwater in the Netherlands, This pap er focuses on nutrient emissions from agriculture, emphasizing nutrien t loads to surface waters, and strategies and perspectives to reduce t hese emissions, Although adverse environmental effects of intensive ag riculture have been known for several Sears, it was not until 1987 tha t stabilization of animal manure production and application began, Sin ce 1991 manure application rates have been reduced, Recently, applicat ion standards hs re been replaced by agriculturally inevitable nutrien t losses and environmentally acceptable nutrient losses and these loss es are reduced to an equilibrium fertilization in 2010, defined as the supply of manure and fertilizers that meets crop uptake and compensat es for inevitable losses. In the 1980s, the most important tool to man age nutrient losses was a manure bookkeeping; recently a mineral bookk eeping has been introduced, Agricultural nutrient emissions to and the ir impact upon surface waters have been estimated from field experimen ts and model calculations, which indicate that the proposed legislatio n will not significantly improve water quality, Increasing areas will be saturated with P, especially where intensive livestock farming is l ocated on sandy soils, Tailor-made regional programs are necessary to achieve ecological restoration of surface waters, with priority for ca tchment areas with vulnerable receiving waters, These programs may con sist of a further reduction of nutrient application rates, hydrologica l measures, selection of crops that extract P from the soils or measur es to increase the P adsorption capacity of the soil, and buffer strip s.