Magister Scientiae - MSc (Botany)

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a comparative study of the influence of different copper concentrations on the growth, chemical composition and activities of certain copper containing enzymes in atriplex nummularia lindl. and a. vestita (thunb.) Aell.
(University of the Western Cape, 1990) Green, D H; Aalbers, J
The total amount of native copper in soil depends on the amount of copper in the parent material (Tisdale .et .al.1968). It is usually in greater concentration in the soil than in parent rock because of weathering of the parent rock and the concentration of the element in the upper soil horizons by growing plants. Copper in parent rock exhibits typical chalcopyrite behaviour in that its abundant and stable minerals are sulfides rather than silicates or oxides (Mordtveldt .et .a.J. . 1972). B the most abundant of the copper minerals is which is common in igneous and sedementary rocks. The average ooppe r cxmte e s between 2 to lOOg.m- 3 soil solutions contain about 0.0-lg.m copper ( Devlin 1983). Concentrations higher than this are often regarded as toxic to plants. Two valences of copper are found in naturally occuring compounds i.e. cu+ and cu2 +. The cu 2 + ion is more commonly found in soils, adsorbed to clay minerals or tied up with organic matter.