PHYTOEXTRACTION OF HEAVY METALS BY HERBAL PLANTS ON TECHNOGENIC SOILS

Abstract

The purpose of the work is to study the specifics of the natural restoration of vegetation on highly toxic embryozems (on the example of the technogenic dump from the large chemical production «Usoliekhimprom», Irkutsk region). It was shown that organo-accumulative embryozem is the first stage of soil formation and the beginning of plant colonization. The level of technogenic soils pollution with heavy metals was assessed by a set of indicators, based on them, organo-accumulative embryozems were classified as soils with an extremely dangerous level of pollution. It was found that the first pioneers on these embryozems were 9 aboriginal species of herbaceous plants: Melilotus albus Medikus., Melilotus officinalis (L.) Pall., Trifolium hybridum L., Trifolium repens L., Trifolium pratense L., Vicia cracca L., Medicago sativa L., Sonchus arvensis L., Chamerion angustifolium (L.) Scop. A number of their unique features allow them to grow in conditions of very strong soil pollution – this is a high level heavy metals accumulation in phytomass, good adaptation of mineral nutrition to hard growing conditions, an increase in biomass during the growing season, and the absence of visual signs of damage. The obtained results give every reason to recommend these herbaceous plants for use as phytoextractors of heavy metals on technogenic dumps.