Natural and induced cadmium-accumulation in poplar and willow: implications for phytoremediation. Plant Soil 227

Abstract

Abstract Potentially poplars and willows may be used for the in situ decontamination of soils polluted with Cd, such as pasturelands fertilised with Cd-rich superphosphate fertiliser. Poplar (Kawa and Argyle) and willow (Tangoio) clones were grown in soils containing a range (0.6-60.6 µg g −1 dry soil) of Cd concentrations. The willow clone accumulated significantly more Cd (9-167 µg g −1 dry matter) than the two poplar clones (6-75 µg g −1 ), which themselves were not significantly different. Poplar trees (Beaupré) sampled in situ from a contaminated site near the town of Auby, Northern France, were also found to accumulate significant quantities (up to 209 µg g −1 ) of Cd. The addition of chelating agents (0.5 and 2 g kg −1 EDTA, 0.5 g kg −1 DTPA and 0.5 g kg −1 NTA) to poplar (Kawa) clones caused a temporary increase in uptake of Cd. However, two of the chelating agents (2 g kg −1 EDTA and 0.5 g kg −1 NTA) also resulted in a significant reduction in growth, as well as abscission of leaves. If the results obtained in these pot experiments can be realised in the field, then a single crop of willows could remove over 100 years worth of fertiliser-induced Cd contamination from pasturelands