Plant availability of lead, cadmium, and boron in amended coal ash

Abstract

Reclamation and revegetation of coal combustion products (ash) are often complicated by high concentrations of metals. The effects of manure and soil additions on the extractability and plant availability of Pb, Cd, and B were examined in ash reclamation plots located in eastern Kansas. Concentrations extracted from the ash by ammonium bicarbonate DTPA were strongly affected by ash type and amendment, but were unaffected by crops. Plant uptake was affected by ash type and plant species and, to a smaller extent, by amendment. Extractable and plant concentrations were very high in some of the material, which was consistent with observed toxicity symptoms. Plant concentrations showed strong, positive correlations with extractable for Cd and B (r values 0.7 to 0.9), but plant Pb was negatively correlated with extractable concentrations (r = −0.66). Correlations were similar for plant uptake vs extractable for Cd and Pb but were much poorer for B.