Effects of Indian mustard and oilseed rape co|cropping on absorbing insoluble cadmium of contaminated soil

Phytoremediation is a promising new method that uses green plants to take up or deloxify Cd from contaminated soils. One species of plant can affect the other co-cropped species, two plant species of co-cropping used for phytoremediation method may improve remediation efficiency. Effects of Indian mustard and oilseed rape co-cropping on the uptake of insoluble cadmium from contaminated soils were investigated in a greenhouse pot experiment with the addition of CdCO_3 to calcareous soil. The results showed that Indian mustard could compete more nutrients than oilseed rape when Indian mustard and oilseed rape were co-cropped. Thus Indian mustard had higher shoot dry weight yield. On the contrary, oilseed rape had poorer shoot dry weight yield when Indian mustard and oilseed rape were co-cropped, because oilseed rape could compete less nutrients or had more soluble Cd in the rhizosphere soil. Indian mustard could activate insoluble Cd, Indian mustard and oilseed Rape co-cropping could enhance their phytoremediation potential for contaminated soil, so Indian mustard and oilseed rape co-cropping could markedly increase Cd concentrations in oilseed rape shoots while Indian mustard showed a marginal increase. Compared with Indian mustard or oilseed rape mono-cropping, Indian mustard and oilseed Rape co-cropping could increase their Cd uptake and Cd remediation rates.