الفهرس يوجد فقط 14 صفحة متاحة للعرض العام
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المستخلص
INTRODUCTION
Few elements have had an interesting history than selenium in terms of soil-plant-animal interrelationships. Nutritional deficiencies of selenium in animals have been demonstrated in many parts of the world where the content or availability of selenium in soils and therefore in crops grown on these soils are extremely low (Combs and Combs, 1986). Although Se is not established as an essential element for the growth of most plants, it plays a vital role in animal nutrition and metabolism. One clearly defined function is as a component of the enzyme; glutathione peroxidase (Spencer, 1982).
Recognition of the essentiality of selenium for animals and poultry and its economic importance, over wide areas of the world, in preventing diseases and in promoting growth and increasing efficiency of feed utilization, demands more precise knowledge of soil and plant relations (Alloway et al., 1967). Low levels of selenium in the soil have been associated with human cancer, heart disease, heavy metal poisoning, various infectious diseases, sexual dysfunction, arthritis, weak eyes, skin and hair problems and aging (Liu and Morris, 1980).
Studies in soils and plants have been carried out throughout the world but in Egypt this element was rarely studied. Now, the agricultural production in our country needs an integrated understand for such element in order to eliminate its toxic effect or to study its adequacy for animal production. Practically small data are available on selenium content in soils, food, and fodder plants in Egypt (Elsokkary, 1980; Soliman, 1981 and Abdellah, 1983). The difficulty of accurately determining selenium, at very low concentration in soils and plants, has probably delayed the work on selenium in Egypt.
The aim of this work was to study the following aspects : (i) status and of selenium in soils of the northern western coast of Egypt (ii) status of selenium in two wild fodder plants grown in the tested soils, (iii) chemical fractionation of selenium, and (v) selenium adsorption by soils.