The effect of liming and the addition to soil of waste organic materials on the contents of calcium and magnesium in cock’s-foot (Dactylis glomerata L.) cultivated on soil contaminated to various degrees with nickel was studied in a pot culture experiment. Plants from four cuts of grass were analysed in the third year of the study. The following factors were taken into account: 1 – contamination of soils with nickel (0, 75, 150 and 225 mg N·kg^-1 of soil); 2 – liming (0 Ca and Ca according to Hh of soil); 3 – waste organic materials (no waste organic materials added, brown coal and rye straw). With increasing nickel content in soil, the magnesium content in biomass of the test plant decreased. The applied liming resulted in an increase in the average calcium content and a decrease in the magnesium content in cock’s-foot. No significant effect of introducing straw to soil on the contents of calcium and magnesium in biomass of the grass was found, while the effect of brown coal was visible both for calcium and for magnesium (in the plants harvested from the objects to which brown coal was applied, the contents of both macroelements were, on average, lower than in the plants harvested from the control objects).