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

Abstract

This paper presents the changes in cultivation practices in Finnish agriculture resulting from the Agri-Environmental Support Scheme of the Common Agricultural Policy of the European Union. Detailed data were collected by interviewing farmers in four different areas of the country. The potential impacts of changes in cultivation practices on phosphorus losses were assessed using a mathematical simulation model. The variables monitored were: fertilization, winter green cover and soil tillage methods in autumn. The use of fertilizers has decreased to meet the requirements of the support programme. Winter green cover has increased in areas to a minimum level of 30% of the cultivated area. However, the potential impacts on nutrient losses were small. There are two reasons for this: the increase in reduced tillage practices is likely to increase the loss of dissolved phosphorus in southern Finland, and the reduction of set-aside has led to slight increases in particulate phosphorus losses. However, the reduction in grassland fertilization rapidly decreased loss of dissolved phosphorus in northern Finland.