This study assessed the influence of liming and waste organic materials on the yield and nitrogen, phosphorus and potassium contents in cock’s-foot (Dactylis glomerata L.) grown on nickel-contaminated soil in the third year of a pot culture experiment. In the experiment, the following factors were taken into consideration: (1) nickel soil contamination (0, 75, 150 and 225 mg Ni·kg−1 of soil); (2) liming (0 Ca and Ca according to 1 Hh of soil) and (3) organic materials (no waste organic materials added, brown coal from a coal mine in Turów and rye straw). Introducing nickel into the soil, regardless of its amount, caused a significant decrease in the total yield of cock’s-foot and increased the nitrogen and potassium contents. Liming caused a significant increase in the yield of cock’s-foot and decrease its potassium content, but it did not clearly differentiate the nitrogen and phosphorus content. The used organic materials (straw and brown coal) caused a decrease in the phosphorus content in the grass biomass.