The effect of citric acid and EDTA on the uptake of Ba, Cu, Mn and Zn by wheat from Maltese calcareous soils

Abstract

The effects of soil amendments on metal uptake by plants are studied to improve micronutrients content in plants. A pot experiment was set up to compare the effect of increasing citric acid and ethylenediaminetetraacetic acid (EDTA) concentrations on the uptake of Ba, Cu, Mn and Zn by Triticum aestivum in two different soils. The chelating agents were applied in two split doses of 5, 10 and 15 mmol/kg citric acid and 0.5, 1.5 and 2.5 mmol/kg EDTA, 28 and 42 days after germination. In terms of treatment, EDTA was the most effective as it induced higher uptake of Zn, Cu and Ba by the wheat. The citric acid treatment was less effective. With regards to Mn, both EDTA and citric acid resulted in a decrease in uptake. The decrease in the uptake of Mn was common for both soils however, the increase in uptake of Ba and Zn was statistically significant in the Tal-Ahrax soil, and the increase in Cu uptake between the control and the treated soil was significantly different in both soils. At high concentrations of EDTA T. aestivum showed extensive signs of necrosis and plant wilt.