Using Sewage Sludge as Alternative Fertilizer: Effects on Turf Performance of Perennial Ryegrass

Abstract

Two years of research were carried out to evaluate the effects of various sewage sludge and nitrogen doses on the turf performance of perennial ryegrass (Lolium perenne L.) under Mediterranean-type climatic conditions. Four nitrogen sources (NS) [NS1: ammonium nitrate (26%), NS2: Bursa City’s wastewater treatment plant’s waste, NS3: biogas production plant reactor waste, and NS4: food processing and canning factory’s sludge waste] were used in the research. Four different nitrogen doses (0.0, 2.0, 4.0, and 6.0 g m−2) were applied. The sewage sludges were analyzed before the start of the research. It was determined that the heavy metal concentrations were below the limit values, and the plant nutrient content was high. Turfgrass color and quality observations were taken in the study, and turfgrass clipping yield was determined. The 4.0 g m−2 nitrogen dose provided acceptable turf color and quality values among the sewage sludges. NS4 showed the best turf performance among the sewage sludges. Despite increased turf color and quality values, sewage sludge produced a low clipping yield. Food processing and canning factories’ sewage sludges can be alternatives to a nitrogen source.