Fertility status, trace elements and heavy metal pollution of agricultural land irrigated from the Gediz River
The effect of the Gediz River, polluted by industrial and domestic wastes, on fertility status and trace elements and heavy metal pollution of agricultural land irrigated from this river was investigated. For this purpose, soil samples were collected in August 1998 between the source of the Gediz River (Murat Mountain) and its mouth (Aegean Sea). Soil samples were collected from 12 different sites along the length of the river basin from 0-30 cm depth. The soils were slightly alkaline, with no salt problem and were poor in organic matter. Total N and available P, K, Mg, Fe and Zn levels were low or average, whereas available Ca, Na, Cu, Mn were present at good and sufficient levels. Thirty three per cent of soils had available B and S of soils had total B levels above the phytotoxic lower boundary. Because of the geographical/geological structure, soil samples from the Gediz source (Sample Site 1) had high amounts of total Fe, Zn, Mn, B, Cd, Ni, Cr and Co. At the second sampling site, total Ni content was also higher than is acceptable according to the national standards set. In addition, in some soil samples the amount of total Cd was above the lower phytotoxic boundary value.
Keywords: Gediz River, heavy metals, soil fertility, trace elements, irrigation