الفهرس 
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Abstract
Several laboratory and greenhouse experiments were carried out to study the effect of certain factors on the availability and plant absorption of zinc, iron, and boron. Those factors were; application of phosphate or ealciuni carbonate to the soil, soil salinization, soil alkalization, soil leaching with saline solutions, and alkali soil aminendments. Ecporients and the obtained results flay be summarized in the following:
1— Phosphate:
Phosphorus was applied to a clay soil at the rates of 0, 10, 20, 50, 100 and 0 nag P/one Kg soil in which kidney bean plants were grown for two months Phosphate applications to the soil were found to decrease Zn concentration in kidney bean leaves significantly. While the levels of both P and B wera increased, those of Pa and Ca were unaffected. All nutrient ratios in plant leaves, except that of Ca/Fe, were affected by phosphate addition to the soil. However, the levels of extractable Zn, B, and Fe from soil were unaffected by P app— J-ication. It seems that phosphorus effect was apparently manifested within the plant environment.