Distribution and forms of heavy metals in some agricultural soils

Abstract

Distribution and availability of heavy metals to plants is important when assessing the environmental quality of an area. The objectives of this study conducted in 2002 were: a) determine the levels of the heavy metals cadmium (Cd), copper (Cu), lead (Pb), manganese (Mn), nickel (Ni) and zinc (Zn) in the agricultural soils of the Bursa plain so that the degree of pollution could be ascertained, b) identify the various heavy metal forms present in soils using a fractionation scheme based on sequential extraction, and c) to find possible dependence on soil physicochemical properties. Total heavy metal content of the soils studied was generally higher than the levels reported in literature for similar soils, suggesting some degree of pollution with heavy metals. The exchangeable forms of the heavy metals, however, were very low, indicating that under present conditions, the availability of heavy metals to plants is at a minimum.