BIOACCUMULATION INDEX AND CONTAMINATION INDEX AS CRITERIA FOR ASSESSMENT OF ACCUMULATION OF COPPER AND ZINC IN BIOMASS OF PASTURE PLANTS

摘要

A 3-year micro-plot study was carried out on effects of differentiated soil properties (soil reaction, the content of fraction below 0.02 mm, a level of soil pollution with heavy metals - Cd, Pb, Cu, Zn) on the uptake speed and accumulation of heavy metals in two species of pasture plants (rye - winter variety cultivated for green mass and barley - spring variety). The effects of investigated factors were assessed based on two indices, I.e. contamination index and bioaccumulation index. The index values obtained for contamination and bioaccumulation indicated an increase of heavy metals uptake by plants with rising soil pollution with these elements. The highest index values for both zinc and copper were obtained on strongly acidic soils, and they were dropping off with an increase of soil pH. Soil granulometric composition had the smallest influence on contamination index and bioaccumulation index. In general, the higher index values were obtained on light soil when compared with medium soil. Irrespective of soil properties, higher bioaccumulation index for Cu and Zn was identified in the case of rye cultivated for green mass while the index values for plant contamination were comparable for both tested plant species.