The impact of adding a natural clay sorbent such as halloysite on the content of selected heavy metals in the biomass of common orchardgrass (Dactylis glomerata L.) was studied in a pot experiment. The study was conducted on mucky soil enriched anthropogenically with heavy metals, whose values exceeded permissible standards of soil quality and values of the geological background. The experiment included three variants with differentiated percentage of halloysite, i.e. 10%, 30% and 50%, as well as two control cultivations. The results confirm the impact of halloysite on the physicochemical properties of soil, consisting in increased soil pH and sorption capacity. Addition of halloysite to soil also differentiated the quantity of crop yield and concentration of heavy metals in the plant and soil. Halloysite was found to have an inconsistent impact on the concentration of heavy metals in the biomass of common orchardgrass, which was proven by some elevation in the level of heavy metals and a higher bioaccumulation factor (BAF). Halloysite constituting 50% of the mass of substrate substantially  increased the consumption of Pb and reduced the sorption of Cr. Addition of halloysite stabilised Zn and Cu in soil. The results of our preliminary investigation indicate that addition of halloysite to soils with excessive concentrations of heavy metals influences the level of soil sorption to the extent which may be effective for soil remediation.

21.2.2016