PLANT UPTAKE OF CADMIUM, ZINC, AND MANGANESE FROM FOUR CONTRASTING SOILS AMENDED WITH Cd-ENRICHED SEWAGE SLUDGE

Abstract

ABSTRACT Studies on the uptake of cadmium, zinc and manganese from Cd-enriched sewage sludge (0–80 mg Cd kg−1) amended Ultisol, Alfisol, Entisol and Vertisol by maize (Zea mays L.) followed by mung bean (Phaseolus aureus Roxb.) revealed that in general, there was a progressive reduction in the dry matter yield of both the crops due to enhanced Cd concentrations in the soil-sludge mixture in all the soils except Ultisol. Significant enhancement in the Cd content of shoots of both the crops with increased sludge Cd was also noticed. Both native and Cd-enriched sewage sludge amendments enhanced the Zn content significantly but resulted in variable uptake of Mn by maize and mung bean shoots. Data on DTPA extractable Cd from soils (Ultisol, Alfisol and Entisol) after first crop (maize) harvest correlated significantly with forage Cd of second crop (mung bean) which indicated significant residual levels of Cd available for plant uptake.