Change of availability and Fractions of Zinc in the Rhizosphere of maize in contaminated soil treated with chelators

Document Type : Complete scientific research article


Background and Objectives: Availability and fractions of zinc are different in the rhizosphere compare to bulk soil according to different biological and chemical characteristics of rhizosphere. This study was conducted to investigate change in availability and fractions of zinc in the rhizosphere of maize (hybrid (KSC.704)) in a contaminated soil treated with chelators (EDTA, citric acid and poultry manure extract) in greenhouse condition.
Materials and Methods: Citric acid and EDTA were used at concentrations level 0, 0.5 and 1 mmol kg-1 soil and poultry manure extract at concentrations level 0, 0.5 and 1 g kg-1 soil. Three seeds of maize were plant in the rhizobox. After 10 weeks, plants were harvested and rhizosphere and bulk soils were separated. Dissolved organic carbon (DOC), microbial biomass carbon (MBC) and available Zn (by using 4 chemical procedures including DTPA-TEA, AB-DTPA, Mehlich3 and Rhizosphere-based method) and Zn-fractions were determined in the rhizosphere and bulk soils.
Results: Rhizosphere soils properties was different with bulk soils. The results showed that DOC and MBC in the rhizosphere soils were significantly (p Conclusion: The results of this research showed that availability of Zn in the rhizosphere soils are smaller than the bulk soils. The maximum amount of Zn in the EDTA treatment (1 mmol kg-1) and the least amount of Zn in control condition, were exteracted. There was not statistically significant differences between both levels of poultry manure extract on Zn availability.