Organic amendment can affect the heavy metal uptake of the inoculated plant with root stimulating microorganisms which was cultivated in contaminated soil

Reducing the entry of heavy metals into the food chain in plant cultivated in the areas contaminated with heavy compounds or petroleum compounds is one of the main environmental issues. This research was conducted to evaluate the role of co-inoculation of wheat with piriformospora indica and pseudomonas putida on plant Cd concentration which has been planted in the Cd and petroleum hydrocarbon -polluted soil and treated with Zn oxide nanoparticles and agricultural steel slag. Treatments consisted of Cd-polluted soil (0, 10 and 20 mg kg-1 soil) that was amended with 0 and 2 % (W/W) Zn oxide nanoparticles and agricultural steel slag and the wheat plant that was co-inoculated with P.indica and P.putida that which was cultivated in a soil that was naturally polluted with petroleum hydrocarbon. After 90 days, plants were harvested and the Cd concentration was measured using atomic absorption spectroscopy. In addition the degradation rate of petroleum hydrocarbon in the soil was determined. Plant co-inoculation with P.indica and P.putida significantly decreased and increased the plant Cd concentration and degradation rate of petroleum hydrocarbon in the soil by 13.1 and 14.9%, respectively. In addition, using 2 % (W/W) Zn oxide nanoparticles and agricultural steel slag significantly decresed the plant Cd concentration by 18.2 and 15.4%, respectively. It can be concluded that plant co-inoculation with P.indica and P.putida had additive effect on degradation of petroleum hydrocarbon in the soil that was amended with Zn oxide nanoparticles and agricultural steel slag.