Contents of Cu, Ni and Zn in smelter-polluted soil–plant systems

Abstract

Intact soil profiles including litter layer and ground vegetation were taken at five distances (0.5, 2, 4, 8 and 60 km) from a Cu–Ni smelter in Harjavalta, SW Finland. The soil cores were placed in 10 l pots and a 4 year-old, bare-rooted pine seedling ( Pinus sylvestris L.) was planted in each. The containers were incubated for17 months in controlled greenhouse conditions. At the end of the experiment the seedlings were harvested and soil samples were taken from each pot and analysed for Cu, Ni and Zn. The absence of atmospheric metal deposition had no reducing effect on the exchangeable heavy-metal contents of the soil pots. Metal uptake by the plant seedlings during the experiment had a negligible effect on the exchangeable heavy-metal content of the soil cores from the most polluted sites. The increase in both the exchangeable and the total humus Cu, Ni and Zn concentrations in the 0.5 km soil cores during the experiment suggested that there were pools of accumulated metals in the thick litter layer on top of the humus.