The study was conducted in 1998-2000, in the Olsztyn Lakeland, on permanent grassland communities with at least 5% share of the following leguminous and herbaceous species. Trifolium pratense, Trifolium repens, Lotus corniculatus, Lathyrus pratensis, Lotus uliginosus, Vicia cracca, Taraxacum officnale, Achillea millefolium, Plantago lanceolata, Alchemilla vulgaris, Heracleum sibiricum and Cirsium oleraceum. In total, 444 plant samples were analyzed, including 123 collected on organic soils. The objective of this study was to determine the accumulation of potassium, calcium and magnesium by selected species of grassland legumes and herbs, in view of the abundance of the above elements in soil. The analyzed organic soils were characterized by low abundance of potassium and moderate abundance of magnesium, whereas the mineral soils had a very low or low potassium content and a very high or high magnesium content. The habitats varied widely with respect to the calcium abundance. The biomass of the analyzed plant species contained high concentrations of potassium, magnesium and calcium. Plants collected from mineral soils contained more potassium and less magnesium than those growing on organic soils. Taraxacum officinale and Achillea millefolium were rich in potassium, Achillea millefolium, Lotus uliginosus, Heracleum sibiricum, Vicia cracca, Taraxacum officinale and Cirsium oleraceum had a high magnesium content, whereas Cirsium oleraceum, Heracleum sibiricum and Alchemilla vulgaris accumulated the largest amounts of calcium. The ability of dicotyledonous plants to accumulate high concentrations of calcium and magnesium resulted in a low K:(Ca+Mg) ratio.

18.1.2013