Copper and zinc translocation to the above- and underground parts of cultivated oat in model polluted soils

Abstract

The translocation of copper (Cu) and zinc (Zn) into cultivated oat from model polluted organogenic and mineral soils was examined, with each metal tested separately. The metals were mixed into the soil samples as sulfates at the following concentrations (on a metal basis): 0, 50, 100, 200, and 500 mg/kg for Cu; 0, 100, 200, 500, and 1000 mg/kg for Zn. Using atomic absorption and atomic emission spectroscopy, the contents of Cu and Zn in the above- and underground parts of oat plants were measured, along with the acid-soluble and mobile compounds of these heavy metals in the soil types studied. Oat plants that germinated in the polluted soils accumulated Cu and Zn at levels 1.5 to 70 times higher compared to the control ones. Both metals exhibited higher migration rates in mineral soil. The translocation of Zn was more pronounced than that of Cu. As the level of soil pollution increased, the barrier function of oat roots intensified. The addition of 500 and 1000 mg/kg Zn to mineral soil disrupted the barrier function of oat roots, causing the plant to behave as a Zn accumulator. Thus, oat roots serve as an indicator of soil pollution with Cu and Zn, and its aboveground biomass functions as a Cu excluder and an indicator of Zn accumulation in organogenic soil.