PHYTOREMEDIATION OF SOILS BY CULTIVATION ENERGY CROPS

Abstract

Restoring soil fertility and protecting it from pollution is a complex scientific problem today, which requires the use of various physical, chemical and biological means. An important theoretical and applied aspect is the development of new remediation methods to reduce soil degradation under the influence of chemical pollution. The publication analyzes the ecological characteristics of energy crops Miscanthus giganteus L. and Phalaris arundinacea L. as phytoremediators of soils contaminated with heavy metals, pesticides, and petroleum products. The study showed that the cultivation of energy crops on technogenically polluted soils leads to heterogeneous changes in the agrochemical and physicochemical composition of the soil. The reaction of the soil solution, the content of carbon and humus has changed little in 2021–2023. When growing Phalaris arundinacea L. on soils contaminated with petroleum products and pesticides, the content of absorbed bases, easily hydrolyzed nitrogen and mobile phosphorus increased significantly, while the content of exchangeable potassium, calcium and mobile sulfur decreased. Conversely, the cultivation of Miscanthus giganteus L. led to a decrease in the content of macroelements and an increase in the content of exchangeable calcium and mobile sulfur. Cultivation of energy crops led to a significant decrease in the content of toxic substances in contaminated soil, in particular, the content of mobile forms and the mass fraction of heavy metals. The greatest reduction was observed for mobile chromium, which was reduced by 0,55 mg/kg for common warbler and1,06 mg/kg for miscanthus giant in oil-contaminated sites, and by 3,65 mg/kg and 5,25 mg/kg kg in areas contaminated with pesticides, respectively. The total content of stibium decreased by 60 mg/kg in the cultivation of common reed and 69,61 mg/kg in the cultivation of miscanthus giant in the oil-contaminated plots, and by 65,68 mg/kg and 78,35 mg/kg, respectively, in the contaminated plots pesticides. On the investigated areas of growing energy crops, the concentration of cadmium decreased by 0,131–0,193 mg/kg when growing common reed and by 0,187–0,312 mg/kg when growing miscanthus giant. The content of organic pollutants also decreased significantly. The content of organic pollutants also decreased significantly. On the areas contaminated with petroleum products, HCG (sum of isomers) decreased by 0,099 mg/kg during the cultivation of common reed and by 0,121 mg/kg during the cultivation of Miscanthus giganteus, on those contaminated with pesticides by 0,12 and 0,143 mg/kg, respectively. When growing common reed, the content of oil products decreased by 565,52 mg/kg in areas contaminated with oil products and by 1364,14 mg/kg in areas contaminated with pesticides, and when growing giant miscanthus – by 564,15–1160,08 mg/kg. Phenol content was found only in pesticide-contaminated areas and was reduced by half due to the cultivation of energy crops. Therefore, we consider it expedient to grow the energy crops Miscanthus x giganteus and Phalaris arundinacea, as they are promising phytotechnologies for increasing the agronomic value of the soil.