Effects of Fe oxide-based nanoparticles on yield and nutrient content of corn in Cobalt-contaminated soils

Abstract

This study aimed to investigate the efficacy of Fe oxide nanoparticles (NPs) alleviating cobalt (Co) phytotoxicity in contaminated soils. The experiment was conducted in a greenhouse involving Fe oxide NPs (carboxymethylcellulose (CMC)-stabilised and non-stabilised (pure) hematite, goethite, and magnetite) and concentrations of soil total Co (5, 25, 65, 125, and 185 mg kg −1). Corn plant was grown in the treated and untreated soil samples and harvested after 60 days. Results indicated that by increasing the concentration of Co in soil from 5 to 25 mg kg −1, the growth parameters and the concentrations of K, P, Fe, and Zn in the shoots of corn increased. However, in soil samples with total Co concentrations of 25 to 185 mg kg −1, the growth and concentrations of nutrients in plant aerial parts declined. At low concentrations of Co (5 and 25 mg kg −1 soil), the application of pure Fe oxide NPs and composites inhibited corn growth as well as concentrations of plant nutrients in the shoots. At high concentrations of Co in soil, the application of treatments, especially stabilised goethite, reduced the accumulation of Co in the corn plant and enhanced its growth by increasing the concentrations of nutrients in plant aerial parts. This study suggests that the efficacy of treatments in enhancing corn growth depends on the total Co concentration of soil.