The estimation of Miscanthus×giganteus’ adaptive potential for cultivation on the mining and post-mining lands in Ukraine

Abstract

The possibility of Miscanthus×giganteus cultivation as an energy crop on the different types of mining rocks was studied. It was revealed that a loess-like loam and red-brown clay with the added black soil were the most suitable for plant growing. The yield of dry above-ground biomass ranged from 4.3 to 6.8 t DM ha⁻¹ after the first year of cultivation and from 8.9 to 9.7 t DM ha⁻¹ after the second year while using these substrates. The application of amendments stimulated the growth and development of plants and increased productivity from 50 to 140%. M.×giganteus showed sufficient tolerance and good enough growth on the geochemically active dark-gray schist clay with yield from 2 to 3 t DM ha⁻¹ after the first year of cultivation already. For plants grown on the different strata of dark-gray schist clay, the thermal decomposition of the biomass took place in four stages in the temperature range from 30 to 640 °C. The samples grown on stratum 0–20 cm showed the highest reactivity with a peak 30.6%/min at 290 °C. There were differences in the concentrations of determined heavy metals: iron, zinc, copper, and lead in the plant tissues depending on the layer depth of dark-gray schist clay from 0 to 20 cm to 40–60 cm. The relatively limited content of heavy metals in the above-ground biomass was due to the preferential accumulation in the roots.