Content of selected macroelements in the aerial and underground biomass of plants from old stands of the genus Miscanthus

Old plantations of grasses used for soil remediation or for energy purposes are capable of the uptake and bio-accumulation of macro- and microelements found in soil. The aim of the present research has been to determine the content of calcium, magnesium, sodium and potassium in the aerial and underground parts in three grass species representing the genus Miscanthus, derived from a 12-year-old M. sinensis plantation and 10-year-old plantations of M. sacchariflorus and M. giganteus. The content of the elements in the biomass of grasses varied. It depended on a species as well as a place of bioaccumulation in plant organs and it was significantly higher than the soil content of these elements. The aerial parts of grasses, especially leaves, accumulated mostly calcium, potassium and magnesium. In the underground parts, mostly in roots, the plants accumulated potassium, calcium and sodium. The plant rhizomes accumulated magnesium in the amounts comparable to the content of this element in leaves. Depending on the sampling depth in soil, a higher content of calcium and potassium was identified in the 0-15 cm horizon than in the 15-30 cm layer. Magnesium and sodium demonstrated the opposite dependence. To illustrate the effect of the content of the macroelements studied in soil on their content in the grasses analyzed, the bioaccumulation factor was determined to define the ratio of an element’s concentration in the plant to its concentration in soil. It shows that the highest capacity for the uptake of the analyzed macroelements from soil was reported in M. sinensis and the lowest appeared in M. sacchariflorus. Grasses of the genus Miscanthus are able to accumulate considerable amounts of macroelements in their organs. After the plantation is terminated, it is a considerable soil-enrichment source.