Effects of Gamma Irradiated and Non-Irradiated Sewage Sludge on Uptake of Micronutrients and Heavy Metals in Basil

To evaluate the effects of different levels of gamma irradiated and non-irradiated sewage sludge on uptake of micronutrients (copper, zinc, iron, nickel and manganese) and heavy metals (cadmium and lead) in root and shoot of basil, a greenhouse experiment was conducted in a completely randomized design with three replications. The treatments consisted of 0, 15, 30 and 60 g.kg-1 of sewage sludge exposed to gamma radiation at doses of 0, 5, 10 and 20 kGy. The results showed that addition of 15 and 30 g sewage sludge kg-1 soil with each irradiation dose increased root and shoot dry weights and reduced their at 60 g.kg-1. The application all levels of irradiated and non-irradiated sewage sludge increased the uptake of copper, nickel, lead, zinc, manganese and iron in root and shoot compared to the control. The maximum uptake of copper, zinc, iron, manganese, lead, cadmium and nickel in root and copper, zinc, lead and cadmium in shoot was obtained in 30 g. kg-1 sewage sludge irradiated with 20 kGy absorbed dose. The maximum uptake of iron, manganese and nickel in shoot was revealed in 30 g.kg-1 sewage sludge irradiated with 5, 5 and 10 kGy, respectively. The results showed that the basil herb has the high ability to absorb and transfer of metals to shoot. Therefore, the use of basil plants treated with sewage sludge in human nutrition as fresh and spicy should be done with caution.