Immobilization and phytoavailability of cadmium in variable charge soils. II. Effect of lime addition

摘要: The effect of pH-increases due to Ca(OH)2 and KOH addition on the adsorption cadmium (Cd) was examined in two soils which varied their variable-charge components. immobilization phytoavailability Cd from one soils, treated with various levels (0–10 mg kg−1 soil), further evaluated using mustard (Brassica juncea L.) plants. Cadmium soil by a chemical fractionation scheme. increased pH, thereby increasing Cd, being more pronounced dominated variable charge There greater increase Cd2+ KOH-treated than Ca(OH)2-treated soil, is attributed competition Ca2+ for adsorption. Increasing enhanced concentration plants, resulting decreased plant growth (i.e., phytotoxicity). Although effectively reduced phytotoxicity, uptake at highest level, probably competition. significant inverse relationship between dry matter yield solution. Addition soluble + exchangeable fraction but inorganic-bound fractions soil. Since there no direct evidence CdCO3 or Cd(OH)2 precipitation used experiment, alleviation phytotoxicity can be primarily pH-induced increases negative charge.