Cadmium uptake potential of Brassica napus cocropped with Brassica parachinensis and Zea mays.

Cadmium uptake potential of Brassica napus co-cropped with B. parachinensis or Zea mays plants in split pot (allow the solutes to pass but prevent the interaction of roots between compartments) experiments was evaluated. Plants were grown in split pots filled with soil spiked at 0, 3, 6, 12, 25 and 50 mg Cd/kg soil. Biomass and Cd uptake were determined after 6 weeks, and rhizospheric soil solutions, extracted using soil probes, were analyzed for pH and water soluble Cd at weekly intervals. Cadmium treatments affected the biomass. Cadmium concentration in the shoots of B. napus was higher when co-cropped with B. parachinensis and significantly higher with Z. mays; however, the biomass was negatively affected implying the higher nutrient apportionment to the crop plants than B. napus. Concentration of Cd in B. napus was higher in shoots than in roots as revealed by shoot/root Cd quotient and was always >1; the quotient for B. parachinensis was approximately 1 and that of Z. mays was <1, indicating the potential of Brassicaceae members to translocate the Cd to aboveground tissue. Results indicate the feasibility of co-cropping method to clean the Cd contaminated soils.