The effect of sewage sludge on the growth and mineral nutrient content of spinach

With the increasing world population, many problems arise. One of them is urban sewage sludge and its disposal. In the present thesis work, an experiment was conducted in greenhouse conditions to determine the effect of increasing levels of sewage sludge on the growth and nutrient content of spinach plant (Spinacia oleracea cv. Matador). In the experiment, sewage sludge was applied at the doses of AC0: 0, AC1: 10, AC2: 20, AC3:30, AC4: 40 and AC5: 50 g kg-1 before sowing the seeds. As a result of the experiment, the fresh and dry weights of the plants and the concentrations of N, P, K, Mg, Ca, Fe, Cu, Zn and Mn were determined. According to the research results, the sewage sludge application were determined by significantly affected fresh and dry weight of the spinach plant and the N, P, K, Ca, Fe, Cu, Mn and Zn concentrations, except Mg. Sewage sludge applications significantly decreased the fresh and dry weight of the plants compared to control and first dose. While the N, P and Ca concentrations of the plants were increased especially in 40 and 50 g kg-1 AC applications, the K concentration decreased at 10 and 20 g kg-1 doses. When the micro element concentrations of the plants were investigated, while Fe and Cu concentrations decreased with 20 and 30 g kg-1 AC applications, Zn and Mn concentrations increased with 40 and 50 g kg-1 AC applications. In conclusion, it has been stated by many researchers that even if the chemical content of the sewage sludge we use in practice is in the non-hazardous range, those who will use it for agricultural purposes should be careful. It should not be forgotten that the application of sewage sludge to the soil without analysis, clarification and consecutively application will cause negative results on the plant and soil.