Chemical Pools of Cd in Sludge-treated Soils and their Contribution to Rajmash (Phaseolus vulgaris. L)

To study the influence of application of organically complexed Cd on Rajmash (Phaseolus vulgaris L.), a pot experiment was conducted on ten sewage sludge-treated old alluvium, non-calcareous, and non-saline soils of Patna wherein a rajmash crop was grown after treatment with 0 and 5 mg kg⁻¹ isotopically tagged and organically-complexed Cd. The results indicated that the application of Cd through cadmium-fulvic acid complex in soils did not influence the dry matter yield of the crop, though it significantly increased the concentration of Cd in the plants and its uptake by the crop. The soil organic carbon content, cation exchange capacity, clay content and pH of the soils were found to be the dominant determinants of Cd in plants and its uptake by the crop. The path analysis and stepwise regression analysis indicated that the water soluble + exchangeable Cd and organically complexed Cd were the two major chemical pools of Cd in soils responsible for supply of Cd to the plants.