Plant Uptake of Cadmium, Zinc and Manganese from Soils Amended with Increasing Levels of Cd-enriched Sewage Sludges and City Composts

Greenhouse pot culture experiments were conducted to evaluate the uptake of cadmium (Cd), zinc (Zn) and manganese (Mn) by two successive maize (Zea mays L. var. Golden Bentham) crops from increasing levels of Cd-enriched sewage sludge and city compost amended Ultisol, Alfisol, Entisol and Vertisol. In general, significant yield reduction of maize shoots of both first and second crops was obtained only in Ultisol and Alfisol amended with higher rates of Cd-enriched sewage sludge/city compost. Amending the four soils with Cd-enriched sewage sludge/city compost resulted in significantly higher accumulation of Cd and Zn in the successive maize crops. The plant tissue concentration of Mn was significantly reduced in Ultisol, whereas, an enhancement was noticed in Alfisol and Entisol and no significant differences were obtained in Vertisol. Results further suggest that care has to be taken while amending soils (acidic soils in particular) with sewage sludges and city composts containing high amounts of Cd.