EFFECT OF TREATED SEWAGE SLUDGE APPLICATIONS ON HEAVY METAL CONCENTRATIONS OF CORN AND SECOND CROP WHEAT GROWN IN SANDY LOAM SOIL

The objective of this study is to determine effect of treated sewage sludge (TSS) rates and mineral fertilizer applications on heavy metal concentrations of corn and second crop wheat grown in a sandy loam soil. The experiment was conducted in the experimental fields of Ege Agricultural Research Institute during 2011-2012 in Menemen-Izmir. Study area is in the Western Anatolia region of Turkey (38 degrees 56'87.96"-38 degrees 56'91.02"N; 27 degrees 03' 57.52"-27 03'58.61"E). The field study was conducted in 20 parcels in a randomized-block design with four replications and five different applications including control, mineral fertilizer, treated sewage sludge 12.5 tha(-1); 25.0 tha(-1); 37.5 tha(-1) as dry matter. The parcels dimensions were 3 m width and 3 m length. Corn (Zea mays L. var. ZP 737) was the first crop, wheat (Triticum durum L. var. Ege 88) was second crop. Corn and second crop wheat samples were taken at the end of vegetation periods in two years. Increasing TSS applications to soil resulted in significantly increased concentrations of Pb in corn grain. But it was under threshold values. The heavy metal contents of corn seeds were within the normal limits for Cr, Cu, Ni, Pb and Zn while Cd was not present in corn seeds. On the other hand the heavy metal contents of second crop wheat seeds were within the normal limits for Cd, Cr, Cu, Ni and Zn while Pb was not present in wheat seeds.