The Effect of Zinc Nutritional Element and Fuel Oil Pollution on Lead Sorption by Wheat Plants in a Soil Treated with Vermicompost under Drought Stress

Considering the importance of heavy metal pollution and fuel oil on human health, this research was done to investigate the effect of zinc (Zn) nutritional element and fuel oil pollution on lead (Pb) sorption by the wheat plant in a soil treated with vermicompost under drought stress.

The current research was conducted as a factorial experiment in the form of a randomized complete block design. The amount of biodegradation of fuel oil in soil was measured by weight method and the amount of Pb and Zn in the wheat plant was extracted by hydrochloric acid (HCl) 2N and then measured by atomic absorption device.

The application of 15 and 30 t/ha of vermicompost decreased the amount of Pb sorption by the wheat plant by 12.3% and 13.8%, while the bio-degradation of fuel oil increased by 13.9% and 22.2%, respectively. Application of 40 kg/ha of pure Zn in the form of Zn sulfate and Zn chelate caused an increase in the biodegradation of fuel oil in the soil by 21.4% and 32%, respectively. Meanwhile, the activity level of ascorbate peroxidase (APX) enzyme decreased by 11.4% and 12.8%, respectively.

Using 40 kg of pure Zn from the Zn sulfate and chelate source has been able to play an effective role in reducing the Pb concentration in the wheat plant cultivated in the soil contaminated with fuel oil. The application of vermicompost has also played an effective role in reducing the availability of Pb in the soil.