Lead phyto-remediation by corn (Maxima CV.) and white clover in monoculture and mixed culture system in a Pb polluted soil

Lead is a dangerous heavy metal for human health. This research was conducted to study the potential of a new Iranian corn (Maxima CV.) and white clover in monoculture and mixed culture for phytoremediation of Pb in a Pb polluted soil.
The experimental treatments consisted of corn and white clover in a mixed culture (with 10 and 20 plant density) and either corn or white clover in a monoculture system (with 10 and 20 plant density) in a Pb polluted soil (800 mg Pb (kg soil)-1) at 60 and 90 days of experiment. Plant and soil Pb concentration were measured using atomic absorption spectroscopy.
Root and shoot Pb concentration of corn and white clover were significantly increased in a mixed culture system relative to mono culture system. In addition, the increase of white clover density from 10 to 20 in a mixed culture system caused a significant increased Pb concentration in root and shoot of corn and white clover. The highest Pb translocation factor (TF) and shoot Pb concentration were observed in white clover in a mixed culture of corn and white clover (with 20 plants density).
The results of this study showed that the Pb concentration of corns shoot in a mixed culture system with corn and white clover (20 densities) was three times higher than that of the monoculture system.