Reducing the heavy metals toxicity in sludge amended soil using VA mycorrhizae

ABSTRACT

A pot experiment was conducted to evaluate the role of VA mycorrhizae as a biological agent in reducing the toxicity of heavy metals. A newly reclaimed soil from Ismailia Governorate was supplemented with sewage sludge from two sources at five different rates 0.0, 0.5, 1.0, 2.0 and 4.0%. One half of each treatment was inoculated with VA mycorrhizae. Application of sewage sludge up to 2% increased faba bean growth, nodule number and weight and phosphorus and nitrogen contents. Inoculation with VA mycorrhizae also induced significant increase in these parameters as compared with the uninoculated treatments. Plant Zn, Mn, Cu, Ni, Cd, Pb, and Co contents were increased with the application of sewage sludge. In the sewage sludge treated soil where the heavy metals were present in high concentrations, inoculation with VA mycorrhizae reduced the concentration of heavy metals. This indicates the role of VA mycorrhizae in reducing the hazardous effect of heavy metals when present in high levels in the media of growing plants