Growth characteristics and response of wheat to cadmium, nickel and magnesium sorption affected by zeolite in soil polluted with armaments

Abstract

The presence of large heavy metal concentrations in soil polluted with chemical weapons causes serious operational restrictions against cultivation of agricultural crops like wheat. To solve this problem, the usage of zeolite has been proposed as one of the most efficient practical approaches. The main objective of this research is the investigation of the influence of natural Iranian zeolite on sorption of cadmium (Cd²⁺) and nickel (Ni²⁺) and the investigation of growth characteristics of wheat in soil polluted with chemical weapons. The experiments were carried out in factorial arrangement in a randomized complete design with three replications during 2015-2016 crop season. Treatments with four levels of zeolite included: a₁) 0%; a₂) 0.5%; a₃) 1.5%; and a₄) 2.5% of soil weight and two soil samples, one obtained from out of the war zone (without contamination) (b₁) and other was from contaminated soil to weapons (b₂). Results showed that the polluted soil led to a significant enhancement in amount of Cd²⁺ and Ni²⁺ in shoots and roots of wheat. In addition, the findings revealed that the application of zeolite caused a significant reduction in Cd²⁺ and Ni²⁺ concentrations in shoots and roots and significantly increased dry matter, chlorophyll index and magnesium (Mg²⁺) concentration in wheat. In general, results showed that zeolite released nutrients and stabilized heavy metals in polluted soil and the negative effect of soil polluted by toxic heavy metals was reduced in the plant, which lead to decontamination of soil and increase in safety of environment.