INFLUENCE OF TREATED SEWAGE SLUDGE APPLICATIONS ON CORN AND SUCCEEDING WHEAT YIELD AND ON SOME PROPERTIES OF SANDY CLAY SOIL

The objective of this study was to determine influence of treated sewage sludge (TSS) rates on corn and wheat yield and on some properties of sandy clay soil. The field study was conducted in the Randomized Block Design with four replications and five different applications including control, mineral fertilizer and TSS (12.5; 25.0; 37.5 Mg.ha(-1) as dry matter). Corn (Zea mays L. var. ZP 737) was the first crop, wheat (Triticum durum L. var. Ege 88) was the succeeding crop. Soil samples were taken five times in two years. Increasing TSS applications resulted in significantly increased total biomass and grain yield of corn. However, grain yield of succeeding wheat did not change significantly. Increasing TSS aplications were significiantly increased total N, available P and K, pH, total salt and organic matter content of sandy clay soil. However, CaCO3 and cation exchange capacity values of soil did not change significantly. Due to decomposition of TSS in the soil, effect of TSS levels on soil properties decreased in the last sampling periods. Thus, it can be recommended that 37.5 Mg.ha(-1) TSS as dry matter can be added once in 2 years for improving plant nutrients and soil properties of sandy clay soil.