Enhanced phytoremediation capacity of a mixed-species plantation of Eucalyptus globulus and Chickpeas

The objective of this research was to determine the phytoremediation efficiency for a mixed plantation of nonnitrogen- fixing Eucalyptus globulus with nitrogen-fixing Chickpeas in soil contaminated by heavy metals including Cd, Cu, Hg and Pb. Plants in the mixed-species systemproducedmore biomass, circulatedmore nutrients and water and absorbed more toxicmaterials due to the nitrogen fixation of Chickpeas and the generation of root and canopy stratification, which reduced nutrients and light competition. It would take, respectively, 40, 68, 4225 and 127 years to reduce the concentration of Cd, Cu, Hg and Pb in the soil to safe levels, which is approximately half the time needed to achieve the same goal for Eucalyptus globulus or Chickpeas monocultures. The mixed cultivation enhances the phytoremediation efficiency of Cd and Cu contaminated soil significantly, but it is ineffective in reducing the Hg level in soil because of its low bioavailability. (C) 2017 Elsevier B.V. All rights reserved.