Effect of Vermiculite Soil Amendment on Immobilization of Selected Heavy Metals of Rhizospheric Zone of Maize

Abstract

ABSTRACT The elevated level of metals in the soil increases the assimilation of these metals by plants causing a serious health risk to humans. A series of pot experiments were conducted to study Pb, Cu, and Zn uptake by Zea mays to investigate the role of vermiculite for metals immobilization in the soil root zone. The metals accumulation was decreased (13.17% to 29.21% in above-ground parts and 4.18% to 69.74% in roots) and total plant biomass increased (1.43% in control soil and 10.54% in polluted soil) in vermiculite amended soils. The effective immobilization of metals in vermiculite amended soil was revealed by decreased values of translocation factors for root-stalk and subsequently for stalk-leaves under varying metal concentrations. Vermiculite amendment to soil had no observable effect on the chemical structure while there were few changes in the functional group of the soil structure. The study reveals that vermiculite can be amended to the soil for reducing phytoavailability of toxic metals to plant uptake and in return flow processes for controlling food-chain contamination and groundwater pollution without compromising with crop production.