effect of applying sunflower residues as a green manure on increasing zn concentration of two iranian wheat cultivars in a pb and cd polluted soil

Background: this research was investigated to evaluate effect of applying sunflower residues as a green manure on increasing zinc (zn) concentration of two iranian wheat cultivars in a pb and cadmium (cd) polluted soil.methods: treatments included the application of sunflower residuals grown in a zn-polluted soil at two levels of 0 and 8 t/ha, two wheat cultivars in a soil contaminated with pb (0, 400 and 800 mg pb/kg soil) and cd (0, 5 and 10 mg cd/kg soil). after 7 months of the experiment. plant pb, zn and cd concentrations were measured using atomic absorption spectroscopy. results: the highest root and shoot zn concentration of wheat plant was belonged to the back cross cultivar. addition of 8 t/ha sunflower residues in soil without pb and cd pollution increased the root zn concentration of back cross and kavir cultivars by 12 and 16%, respectively. the highest and lowest zn translocation factor of wheat plants was belonged to back cross and kavir cultivars, respectively.conclusion: applying sunflower residues has a significant effect on increasing plant zn concentration and can be useful as a suitable way to increase zn concentration of wheat grown in zn deficient and heavy metal polluted soils.