Effect of Nitrogen Fertilization on the Dynamics of Concentration and Uptake of Selected Microelements in the Biomass of Miscanthus x giganteus

This paper presents the effects of nitrogen (N) fertilization on the concentration of selected micronutrients as an important issue in reducing combustion-induced air pollution. We studied the effects of the dose of 60 kg ha−1 N in different terms of biomass sampling on the concentration and uptake of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in the dry matter of the underground and aerial parts of Miscanthus x giganteus in the years 2014–2016. The order of microelement concentrations (mg kg−1) in rhizomes and the aboveground parts of plants was as follows: Fe > Mn > Zn > Cu. N fertilization had no significant effect on the concentrations of the selected microelements in the Mischanthus biomass (except for the Mn concentration in the stems and Cu in the leaves). The results indicated that the quality of the combustion biomass did not worsen under nitrogen fertilization. During the whole vegetation period, the iron concentration increased in the rhizomes and decreased for Zn and Cu. In the aboveground parts of the plant, the concentrations of all tested elements decreased. In turn, the uptake of Fe, Mn, Zn, and Cu (except for Fe in the stems) by rhizomes and the aboveground parts of Mischanthus depended significantly on the N fertilization.