Potential for the utilization of biofuel plant of the second generation of Miscanthus giganteus for phytoremediation of oil-contaminated lands

Reproduction and conservation of soil fertility, protection against degradation and pollution is traditionally one of the priority tasks of the state agricultural policy. The presence of petroleum products in soils causes violation of ecological balance in the soil system, changes in morphological and physicochemical characteristics of soil horizons, in the ratio between the individual fractions of soil organic matter. Therefore, today more and more attention is paid to the development and implementation of innovative technologies for purification of oil-contaminated soils. Phytoremediation is currently considered to be the most promising method for сleaning of polluting in industrialized countries. The material elucidates the results of the study of changes in agrochemical parameters of soil in consequence of oil pollution and сarrying out of phytoremediation, determined the dynamics of the degree of purification of oil-contaminated soils, reducing their phytotoxicity by growing bioenergy culture Miscanthus giganteus. The model experiment was conducted in natural conditions of the scientific-research plot of Poltava State Agrarian Academy. Oil was applied to the soil in the following concentrations: 10, 20 and 40 g/kg. Three weeks after the application of oil into the soil, vegetative shoots of Miscanthus giganteus were planted out in the first year of life. The period of oil degradation in the soil lasted 177 days, of which 156 days – the reclamation period with using the bioenergy plant Miscanthus giganteus. It was found that growing Miscanthus giganteus on oil-contaminated soil with the application of 40 g/kg reduced the content of petroleum products by 13% compared to the control variant – without plants. With increasing concentration of oil pollution after phytoremediation of Miscanthus giganteus, the pH of the soil solution and metabolic acidity increases, the amount of absorbed bases decreases, the intensity of respiration increases significantly. The content of organic carbon in the soil was characterized by the following indicеs: at contamination of 10 g/kg the content of organic carbon reached 4.4%, at pollution of 20 g/kg – 6.1%, and at 40 g/kg – 7.0%, respectively, the content of organic matter was 8.3%, 11.5% and 13.2%, the content of humus – 7.59%, 10.52% and 12.07%. Miscanthus giganteus plants create favorable conditions for the development of microorganisms and increase their activity in consequence of the secretion of nutrients by the roots, improving soil properties. Thus, second-regeneration biofuel plants Miscanthus giganteus can be recommended for phytoremediation of oil-contaminated soils and thus, on the one hand, clean large areas of land, and on the other – to obtain biomass for further energy production, which will be environmentally friendly and economically feasible.