EXCHANGEABLE HEAVY-METALS IN CENTRAL SPANISH SOILS

In this study the available heavy metal ions in soils have been investigated by extraction using 1N NH4OAc, pH 7. The results of this soil analysis revealed a low amount of heavy metal ions extracted. Correlations were obtained from linear regression analysis between Zn, Cu, Pb, and Cd exchangeable ions and soil parameters, and between the heavy element content of both soils and plants. There war a significant negative correlation Zn-exchange capacity and Zn-clay fraction, and a significant positive correlation Cu-CaCO3 and Cd-CaCO3. The relationships between exchangeable ion and total element content were significant for Pb, Cu, and Cd. A significant correlation between plant element concentration and exchangeable ion content in soils was obtained for Cd.