Nutrient losses from agricultural areas in the Gulf of Riga drainage basin

Abstract

Leaching and runoff losses of nitrogen and phosphorus were measured in four catchments in Estonia and Latvia during the period 1994–1997. The losses varied considerably depending on land use and farming practices. In two catchments characterised by cereal production and moderate inputs of plant nutrients, the losses were found to be at a low level, compared to measurements in similar catchments in Norway and Sweden. Very large leaching and runoff losses were recorded in two catchments characterised by heavy applications of pig slurry. In one of these catchments, high losses were recorded even though farming activities ceased in 1991–1992. The effects of slurry applications seem more marked for P than for N. The study shows that the former large state and collective farms that specialised in animal production may still be potential risks for the environmental quality of Estonian and Latvian waters.