In a green house pot experiment, the effects of three amendments, sulphur (S), ammonium sulphate ((NH4)2SO4) and ethylenediaminetetracetic acid (EDTA) were tested for phytoextraction of Cd and Zn by rapeseed (Brassica napus L.). Elemental sulphur was applied as 20.00, 60.00, and 120.00 mg.kg−1 soil. EDTA was tested at a dose of 585.00 mg.kg−1 soil, and (NH4)2SO4) at a rate of 0.23 mg.kg−1 soil. All treatments received a base fertilization (Hogland) before sowing. Plants were harvested after 51 days of growth and shoot dry matter and soil samples were analysed for metal contents.
All amendments caused a significant increase in Cd and Zn contents in plant shoots of all treatments than control treatment. Further, EDTA was most effective for extraction metals concentrations in shoot biomass but the plants showed significant signs of toxicity and yield were severely depressed. The addition of sulfur favorably influenced plant biomass production. The fertilized ammonium sulfate treatment resulted in the highest phytoextraction of Cd and Zn and the amounts of these metals accumulated in plant shoot exceeded by a factor of 4 and 3 respectively. Finally, Brassica napus could be used for soil remediation keeping its other uses which will make the contaminated site income generating source for the farmers.
