Micro-field experiments have been carried out on three types of soil: chernozem (Chernozems by Guidelines, 1990), soddy-podzolic (Podzoluvisol) and peat bog (Histosols) located in various regions of Ukraine. These soils are typical for Eastern Europe (dominant in Ukraine) and differ significantly in their genetical, morphological and agrochemical properties.
The area surface of a single experimental plot was 3 m2 (2.0 m by 1.5 m). Each variant of experiments was carried out in three replicas.
Forage crops, clover and perennial cereal grasses (mix of fescue and rye grass), were chosen for experiments, because they fill a certain place in the human trophic chain and differ significantly in their botanical and physiological properties.
Four heavy metals (copper, cadmium, lead and zinc) were used in the study. Copper and zinc belong to the group of biophyllic elements, and soils of the investigated areas (Northern Ukraine) are considered to be poor in these metals (Grigorjev and Plishko, 1989). Lead and cadmium are the most dangerous for human health and, as a result, they are strictly controlled elements.