To study the relationship among mineralogical composition of soil fractions and
fraction size , on adsorption of zinc in some alluvial soils , two soil sites are
chosen to represent sediments of Tigris and Euphrates rivers.Soils are fragmented to find clay (< 0.2)micron , coarse clay (0.2-2)micron , silt
(2-50)and sand (50-2000)micron fractions are treated with four levels of zinc
solution(ZnSo4.7H2o) , at rates of (0,20,40,60microgram.ml-1) .
The results show an agreement between amount of adsorbed zinc and soil
content of smectite and chlorite minerals. The highest adsorption is in fine clay
and sand of Tigris sediments , which have high content of expansible 2:1
minerals . The results show a negative relationship between amount of adsorbed
zinc and fraction size.
The results show that Zinc adsorption increase with further addition of Zinc to
the samples and the highest zinc adsorbed is in the fine clay in all treatments,
while sand is the lowest.