A study on some trace metals as related to Soil environment

Abstract

In agricultural ecosystems, most trace heavy metals are cycled in plant-water-soil systems, Many environmental factors, naturally or man-made, affect the behaviour and status of heavy metals in soils. The relative,importance of various transfer pathways vary considerably, depending on nature of the element, plant species, soil type, location, and management practices. The distribution of elements between soluble, available, and unavailable fractions is of great importance which affect soil fertility and productivity. Moreover, the accumulation of toxic metals in soil-plant systems attracted the attention of several workers world wide. Land disposal of municipal sewage sludge and effluents is an old practice, that recently has been attracting attention of many workers due to its impact on environment. This system involves using the water and nutrients in sewage effluents on forest and cultivated crops.The concentration of trace elements in soils in areas treated with sewage sludge can be expected to increase with increasing concentrations of these element in the sludge. In Egypt, sewage effluent has been used for crop irrigation for many years (since 1911) in EI-Gabal EI-Asfar farm. Soil environment is affected by this practices in many ways, one of them is its content and status of heavy trace metal. The purpose of this investigation is to study how some heavy trace metals (eleven elements) are affected by irrigation periods distributed in different soil depths, and also to study their content in plants grown in those soils.