Assessing the Efficiency of Sorghum (Sorghum Bicolor) and Common Lambsquarter (Chenopodium Album) in Phytoremediation of Zn From Soil

Heavy metals contamination of soil and plants has very important and vital role in relation to health and life of human and other organisms. The aim of this study was to assess the efficiency of sorghum (Sorghum bicolor) and sommon lambsquarter (Chenopodium album) in phytoremediation of Zn from soil. Efficiency of 0.01M CaCl2, 0.1M NaNO3, and 1M NH4NO3 for extraction of “bioavailable fraction of soil Zn was also compared. Correlation between the Zn concentrations extracted by these methods and plants response (relative yield and shoot Zn concentration) to soil Zn contamination was then evaluated. For this purpose, a calcareous soil sample was contaminated with different concentrations of Zn. Sorghum and common lambsquarter, were grown in pots containing the contaminated soil and were analysed for their Zn concentrations after harvest. Results of this study showed that, common lambsquarter was more tolerant to low and medium concentrations (≤900 mg/kg), but sorghum tolerated high concentration of Zn. Also sorghum was more capable in removal of Zn from soil in comparison to common lambsquarter, so that soils contaminated with low Zn levels (≤900 mg/kg) can be remediated by sorghum. In addition, there was a significant correlation between 1 M NH4NO3-extractable soil Zn and the plants response (relative yield and shoot Zn concentration) to soil Zn contamination.