Effect of sewage sludge and furnace waste on the content of selected elements in the sward of legume-grass mixture

Abstract

Industrial landfills resulting from operations of various industries, particularly power generation, create specific habitat conditions for flora. Among the waste which may be used for recultivation of dumping heaps there is sewage sludge, which contains a considerable amount of nutrients crucial for plants. This investigation aimed at identification of the effect of sewage sludge and furnace ashes on the content of selected elements in a mixture of grass and white clover recommended for furnace ash heap recultivation. The experimental design comprised 6 treatments (each in four replications), which differed in a dose of the supplied sewage sludge and furnace ashes: 1) control (without waste 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 ranged from 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 exclusively on sewage sludge. While assessing the content of macroelements in the plant mixture in view of its fodder value, it was found that the content of Mg and K met the standards set for good quality feeds, the amounts of Ca and Na were below the optimum, whereas the P concentration was close to the optimum value.