Content and accumulation characteristics of the major ore (Zn, Cu, Pb) and mineralization-associated (Cd, Fe, Mn) chemical elements in Medicago falcata growing under technogenic load

The content, features of accumulation and distribution of ore (Pb, Zn, Cu) and related (Cd, Fe, Mn) chemical elements in the biomass of sickle alfalfa growing in the tailings ponds of Altai Mining and Processing Factory (AMPF) and its surroundings were studied. Trace elements in plant samples, as well as in soil samples and in the upper horizons of soils were determined by atomic absorption on a Quant-2mt spectrometer. It was found that the upper layers of the substrates of the old and new dumps were characterized by an increased content of Zn, Cu, Pb, Cd relative to the approximate permissible concentration (APC) and background. Most alfalfa samples were characterized by an increased Zn content (50–135 mg/kg of dry weight). The content of Cu (6.5–25.9) and Cd (0.061–0.989 mg/kg) was higher than the background, but rarely exceeded foreign standards for forage grasses. In alfalfa from the old AMPF tailings dump the Pb content (11.3–18.5 mg/kg) exceeded its content in alfalfa growing in the new dump (1.5–7.1 mg/kg), although the Pb content in the substrates did not differ significantly. The Fe content in alfalfa varied, as a rule, from 69 to 234 mg/kg, but in an uncultivated landfill it reached 461 mg/kg, which is considered excessive. Manganese content in alfalfa dumps of AMPF and the surrounding area (<39 mg/kg) was recognized as a deficient trace element. The highest concentrations of Zn, Cd, Cu, and Pb in alfalfa roots and in the upper layer of the substrate were determined at a point on the surface of a new dump near a spontaneous landfill, as an example of the combined effects of 2 environmental pollution factors. The high concentrations of Zn and Cd in alfalfa growing on the soil-like substrate of the new reclaimed landfill can be explained by the additional intake of toxins from the surface of the leaf blade from dust deposited on it, as well as the absorption of metals by the roots from the material of the landfill itself, buried under the soil-like ground. The intensive absorption of Fe and Pb by alfalfa in the old landfill is due to the acidic reaction of the substrate medium, which increased the mobility of metals and their accessibility to plants.

sickle alfalfa, Altai Mining and Processing Factory (AMPF), tailings dumps, substrate, heavy metals (HM), biological absorption coefficient, concentrations and accumulation of HM