Effect of Applying Chemical Fertilizers on Concentration of Cd, Pb and Zn in Agricultural Soils

Abstract

Background ONowadays uncontrolled uses of chemical fertilizers which have many heavy metals such as Cadmium, Lead and Zinc in addition have economic problems, cause to serious damages in the environment. Therefore uncontrolled application of fertilizers can cause accumulation contaminants in soil, water sources and increasing in plants and human & animalsr food chain. The main objective of this research was to investigate the effects of chemical fertilizers application to increase heavy metals in agricultural soils at directions to prevent contamination in water sources, agricultural products and the best uses of chemical fertilizers. Methods: In this study, 20 soil samples and 5 useful chemical fertilizer samples were collected and investigated. After fertilizer and soil samples were prepared, digested and filtered, heavy metals were determined with using atomic absorption. Results: The results of this study showed that, Cd in Diammonum phosphaten fertilizer 1.25 times, Super phosphate triple 1.7 times and in Macro granular fertilizer 1.5 times were as much as maximum acceptable concentration in chemical fertilizers. Cadmium concentration in all of the Jarghoye (Isfahan) agricultural soil samples 3 to 7 times and in the Mobarake village (Najaf abad) agricultural soil samples 10 to 35 times were as much as maximum acceptable concentration in agricultural soils. But Pb and Zn concentration in all of the agricultural soil samples was less than the amount of maximum acceptable concentration. Conclusion: Phosphate chemical fertilizers were positive effects to increase concentration of Pb and Zn in agricultural soils. Therefore, application of the fertilizer must be more attention because of increasing heavy metals in the agriculture soils and probably increasing heavy metals in food chain.nn