Abstract
Data on dissolved copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), and aluminum (Al) are presented for surface waters from an agricultural catchment transformed into forest in northwest Spain. The use and management types carried out in the catchment were as follows: agricultural catchment with spreading of slurries using a conventional tank, agricultural catchment with intensive slurry application, and reforested catchment without slurry application. Concentrations of the metals in the runoff ranged widely (Al, 18–204; Fe, 7–374.5; Mn, 1.5–680; Cu, 0.29–121.6; Zn, 2.8–164.3 μg L–1). The mean concentrations of studied metals were greatest in the agricultural period. They all present the greatest concentration peaks in the agricultural catchment phase with massive slurry application. This period especially affected the concentrations of dissolved Cu and Mn, as well as those of Zn and to a lesser extent those of Al and Fe. Temporal variations in trace elements at the catchment outlet suggest that dissolved metal concentrations are controlled essentially by the land-use and management practices.