Effect of sewage sludge applications on heavy metal content of sandy loam soil and corn

The aim of this study is to determine effects of treated sewage sludge applications on heavy metal content of sandy loam soil and corn. Treated sewage sludge (TSS) is an ultimate product of municipal wastewater treatment plant. It may be deposited in landfills, in the sea (ocean disposal), under the ground, or (to a certain extent) in the air as a consequence of incineration. In addition TSS can be recycled in various ways, including its use as fertilizer, as a soil conditioner in farmland. The experiment was conducted in the experimental fields of Ege University Faculty of Agriculture Research Application and Production Farm-İzmir. The study was carried out in Menemen Plain located in Gediz Basin. The field study was conducted in 20 plots in a randomized-block design. The plots dimensions were 3 m width and 3 m length. Soil texture of experimental field is sandy loam. The experiment was conducted with four replications and five different applications. These applications are control, mineral fertilizer, dry sewage sludge 1 t/da; 2 t/da; 3t/da. There was no relationship between treated sewage sludge levels and total As, Ni and Pb concentration in soil when compared with control. However, total Hg, Cu, Cr, Cd and Zn concentrations in soil were significantly increased by increasing treated sewage sludge applications. But heavy metals concentrations in soil were lower than the toxic threshold values according to the official limits. Increasing treated sewage sludge applications were significantly increased available Cu and Zn concentrations in soil when compared with control. Applications of increasing treated sewage sludge levels were significantly increased corn yields when compared with control as statistically.