Industrial landfills resulting from operations of various industries, particularly powergeneration, create specific habitat conditions for flora. Among the waste which may beused for recultivation of dumping heaps there is sewage sludge, which contains a considerableamount of nutrients crucial for plants. This investigation aimed at identification of theeffect of sewage sludge and furnace ashes on the content of selected elements in a mixtureof grass and white clover recommended for furnace ash heap recultivation.The experimental design comprised 6 treatments (each in four replications), whichdiffered in a dose of the supplied sewage sludge and furnace ashes: 1) control (withoutwaste admixture), 2) 200 t d.m. of sewage sludge, 3) 200 t d.m. of ash, 4) 150 t d.m. of sludge + 50 t d.m. of ash, 5) 50 t d.m. of ash + 150 t d.m. of ash, 6) 100 t d.m. of ash + 100 t d.m. of ash. The content of macroelements in plants depended on the treatment and rangedfrom 2.58-31.2 g Mg, 3.16-5.85 g Ca, 16.95-18.46 g K, 0.26-1.25 g Na and 2.27-3.37 g P kg–1 d.m. Plants grown exclusively on furnace ashes had the highest content of Mg, Ca and K, whereas the highest P and Na concentrations were noted in plants cultivated exclusivelyon sewage sludge.While assessing the content of macroelements in the plant mixture in view of its foddervalue, it was found that the content of Mg and K met the standards set for goodquality feeds, the amounts of Ca and Na were below the optimum, whereas the P concentrationwas close to the optimum value.