STUDIES ON STATUS OF MANGANESE AND ZINC IN SOME SOILS OF EGYPT

Abstract

This work was conducted mainly to throw some light on the status of Mn and Zn in a clay soil and a sand one taking into consideration: (i) Extractability of both elements in relation to some soil characteristics under water saturation and oversaturation conditions. (ii) Effect of adding organic matter or CaC01 (as crushed limestone) on the transfonnation of Mn among soil fractions during incubation under saturation condition. (iii) Assessing plant response to application of Mn and Zn to both the studied soils upon application of organic matter and crushed limestone. To fulfill these purposes, two stuface soil samples (0-30 em depth) were taken from arable fields in two locations in Giza Governorate. The first soil was a clay soil from Kerdasa and the second soil was a sand soil from Abu-Rawash. The two soils are Entisols, the first soil is Typic Toniorthents, and the second one is Typic Toni psammen ts. The experimental work involved 6 experiments, 1.e. four incubation experiments and two greenhouse ones. The incubation experiments were as follows: (i) the first experiment dealt with Mn in relation to organic matter, in this experiment, the studied soils were incubated at two moisture levels i.e. I 00 and 150 % of soil saturation percentage (SP); (ii) the second experiment dealt with Mn in relation to limestone; (iii) the third experiment dealt with Zn in relation to organic matter and (iv) the fourth experiment dealt with Zn in relation to limestone. For experiment (ii) to (iv) moisture content was 100% SP.