Soils selenium

In 1956 selenium was identified (123) as an essential micronutrient iu nutrition. In conjunction with vitamin E, selenium is effective iu the prevention of muscular dystrophy iu animals. Sodium selenite is adrninistered to prevent exudative diathesis iu chicks, a condition iu which fluid leaks out of the tissues white muscle disease iu sheep and infertility iu ewes (see Eeed ADDITIVES). Selenium lessens the iacidence of pneumonia iu lambs and of premature, weak, and stillborn calves controls hepatosis dietetica iu pigs and decreases muscular inflammation iu horses. White muscle disease, widespread iu sheep and cattle of the selenium-deficient areas of New Zealand and the United States, is insignificant iu high selenium soil areas. The supplementation of animal feeds with selenium was approved by the U.S. EDA iu 1974 (see Eeed additives). Much of selenium s metaboHc activity results from its involvement iu the selenoproteia enzyme, glutathione peroxidase. 

Goldberg, S., and Glaubig, R. A., 1988b, Anion sorption on a calcareous, montmorillonitic soil - selenium Soil Science Society of America Journal, v. 52, p. 954-958. 

In high-selenium soils of some arid regions, selenate is a problem pollutant in the drainage water of irrigated fields, while selenite is not. Develop a plausible argument based on chemical principles to explain this observation. 

Rosenfield and Beath (1964) classified plants into three groups based on their selenium uptake from seleniferous soils (i) selenium accumulator plants which can contain >1,000 mg kg selenium and grow well on high-selenium soils ... 

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