Accumulation Characteristics of Pb,Cd and Zn by Chenopodium ambrosioides L.Intercropping With Maize and Broad Bean

A phytoremediation system consisted of metal hyperaccumulator Chenopodium ambrosioides L. and crops (maize and broad bean) intercropped was exploited to phytoextract metals in polluted soil, in order to explore the feasibility of simultaneous grain production and heavy metal contaminated soil phytoremediation. Pot experiments were carried out to study the effects of intercropping Chenopodium ambrosioides L. (C. ambrosioides) and crops(maize and broad bean) on the absorption and accumulation of Cd, Pb and Zn in plant. The results showed that the biomass of C. ambrosioides,broad bean and maize increased by 134%~217%, 100%~124% and 1.7%~5.6% under intercropping compared with monoculture, respectively. The contents of Pb and Cd in C. ambrosioides increased by 10%~85% and 21%~134%. Besides, soil available Pb and Cd contents of C. ambrosioides increased by 11% and 19%.Then, the transfer coefficient of Pb and Zn in C. ambrosioides was increased, on the contrary, the Cd's reduced. On the other hand, the contents of Pb and Zn in maize decreased by 17%~33% and 10%~34% respectively under intercropping system. Meanwhile, the contents of Pb and Zn in broad bean decreased by 27%~35% and 5%~34%. Furthermore, the available contents of Pb, Cd and Zn in rhizosphere soils decreased by 2.5%~22.7%. The transfer coefficient of Pb, Cd and Zn in broad bean and maize was decreased significantly under intercropping system. The results indicate that contents of Pb, Cd and Zn in C. ambrosioides under intercropping system could be promoted and reduced in crops.