Phytoaccumulation of Cadmium from soil by Populus

Soil contamination with Cd is of concern in many countries throughout the world. Extraction of metals from contaminated soils using high-biomass, metal accumulating Populus has been proposed as a low cost, gentle remediation strategy. In a pot experiment, the phytoaccumulation potential for Cd of 3 poplar species (Populus cathayana, P. prezwaskii, P. yunnanensis) were evaluated on three moderately contaminated soils. Large concentrations of Cd (92 mg kg^-1) were determined in leaves of P. cathayana grown on a soil containing 14.2 mg kg^-1 Cd, resulting in bioaccumulation factors of 27. Total removal of up to 20% Cd after one vegetation period were shown for P. cathayana closely followed by P. yunnanensis and P. prezwaskii. While total Cd concentrations in soils were reduced by up to 20%, 1 M NH4NO3-extractable metal concentrations did not significantly decrease within one vegetation period.