Within the study of transport processes in the spruce forest ecosystem of the Drahanska vysocina Uplands (the Rajec project) in 1976-1990, changes were studied in the chemistry of precipitation entering the forest ecosystem and comparisons of the precipitation water quality were carried out with water quality from intensively cultivated agricultural land. The greatest changes in water quality were found in the Norway spruce stand throughfall and in the surface humus. Marked differences were found between the water quality of a forest spring and the water from an agroecosystem. Relationships were also found between water quality from throughfall and elements accumulation in tree crowns caused by wind transport from surrounding cultivated fields.