Modelling the impacts of management practices on agricultural phosphorus losses to surface waters of Finland

This paper presents the changes in cultivation practices in Finnish agricul ture resulting from the Agri-Environmental Support Scheme of the Common Agr icultural Policy of the European Union. Detailed data were collected by int erviewing farmers in four different areas of the country. The potential imp acts of changes in cultivation practices on phosphorus losses were assessed using a mathematical simulation model. The variables monitored were: ferti lization, winter green cover and soil tillage methods in autumn. The use of fertilizers has decreased to meet the requirements of the support programm e. Winter green cover has increased in areas to a minimum level of 30% of t he cultivated area. However, the potential impacts on nutrient losses were small. There are two reasons for this: the increase in reduced tillage prac tices is likely to increase the loss of dissolved phosphorus in southern Fi nland, and the reduction of set-aside has led to slight increases in partic ulate phosphorus losses. However, the reduction in grassland fertilization rapidly decreased loss of dissolved phosphorus in northern Finland. (C) 199 9 IAWQ Published by Elsevier Science Ltd. All rights reserved.