Assessment of the potential of using sludge compost to fertilize urban lawns

The purpose of this study is to evaluate the effectiveness of using composted sludge as a fertilizer for lawns in urban conditions. An experiment to study the effect of different doses of sludge compost on the productivity of lawn grass mixture biomass (Rheigras lolilum perenne, Festuca rubra, Festuca arunnacea) and soil properties was conducted at the experimental site of S. Seifullin Kazakh State Agrotechnical University, Astana, Kazakhstan. Three doses of sludge were selected: 5, 10, and 15 t/ha. As a result of the experiment, it was found that the greatest biomass of the lawn was obtained when a compost dose of 15 t/ha was applied. In that case, an increase in the activity of soil enzymes and the phosphorus and nitrates content in the soil was observed. The authors formulated a recommendation to use a dose of 10 t/ha of sediment for fertilizer, as this helps to improve soil quality and increase yields. Compost made of sludge increased the content of available phosphorus in the surface layer of the soil (0-20 cm) by 200-300%, and the nitrate content increased by 180-300% compared to the control variant. However, the content of exchangeable potassium changed slightly (5-19%).