EFFECT OF SUCCESSIVE TWO YEARS TREATED SEWAGE SLUDGE APPLICATIONS ON CORN AND SECOND CROP WHEAT YIELD AND SOME SOIL PROPERTIES OF SANDY CLAY SOIL

In this study, effect of successive two years treated sewage sludge (TSS) applications on corn and second crop wheat yield and some soil properties of sandy clay soil (Typic Xerortent) were investigated. The field study was conducted in 20 parcels in a randomized-block design with four repetitions and five different applications including control, mineral fertilizer, treated sewage sludge 12.5 t.ha(-1), 25.0 t.ha(-1), 37.5 t.ha(-1) as dry matter during 2011-2012 in Menemen-Izmir, Turkey. Corn (Zea mays L. var. ZP 737) and wheat (Triticum durum L. var. Ege 88) were sown as the first and second crop respectively. During the experiment, soil samples were taken five times in two years. Successive two years increasing TSS applications to sandy clay soil resulted in significantly increased total biomass and grain yield of corn according to the control. The highest grain yield of wheat as second crop was found with the highest TSS application. Increasing TSS applications were significantly increased total N, plant available P and K, total salt, CaCO3. OM content and CEC of sandy clay soil as average of 5 sampling periods. However, It was found that, there is no statistical relationship between TSS levels and pH values of soil samples of 1st, 2nd, 3th and 5th periods when compared with the control. It can be recommended that 37.5 t.ha(-1) TSS as dry matter can be added for improving plant nutrients and soil properties of sandy clay soil under Mediterranean climate, which are characterized by low OM content and high pH.