Effect of mixed cadmium, copper, nickel and zinc at different pHs upon alfalfa growth and heavy metal uptake

Alfalfa ( Medicago sativa) plants were able to take up metals from a mixture of Cd(II), Cu(II), Ni(II) and Zn(II) in soils. Alfalfa plants were grown in soil-pots contaminated with a mixture of Cd(II), Cu(II), Ni(II), and Zn(II), (at 50 mg/kg each) at pHs of 4.5, 5.8, and 7.1. The plants were fertilized using a nutrient solution, which was adjusted appropriately to the same pH. Plants in the control treatment were grown in the absence of the heavy metals mixture. The growth of the control plants was the same at the three pHs studied and the heavy metal stressed plants also showed similar behavior at each pHs. There were statistically significant differences ( P