SELECTIVE ADSORPTION OF POTASSIUM AND CALCIUM ON SOIL CLAYS AND SOME CLAY MINERALS
Abstract: The current work aims at spotlighting the importance of cation exchange phenomenon as one of the most important processes affecting different properties of soils. Thus, two surface soil samples were undertaken from Burg El-Arab (calcareous soil) and Moshtohor (alluvial, non-calcareous soil), besides their separated clay fractions, the organic matter-free soils and two commercial clay minerals namely attapulgite and bentonite were subjected to equilibration with chloride solutions having different K/Ca ratios varied from 10/90 to 90/10. The obtained results could be summarized in the following:
- Increasing K/Ca ratio in equilibrium solution resulted in a gradual increase in equivalent fraction of exchangeable K on all the exchange materials.
- Values of the investigated selectivity coefficients of all exchange materials tended to decrease with increasing K/Ca ratio in equilibrium solution indicating to the higher preference for K adsorption at the lower K concentrations in soil solution. These values seemed dependent on type of exchange material as well. The variations in calculated selectivity coefficient could be explained on basis of differentiations in mineralogical composition of the used exchange materials.
- Removal of organic matter increased the selectivity coefficients of the investigated soils for K.
- Relatively higher selectivity coefficients for K were shown by bentonite as compared with attapulgite.
- So, it may be concluded that, when soil are fertilized with K, it undergoes exchange reactions through which an appreciable part of it changes to the exchangeable or fixed form and thus it is prevented against loss by leaching.
Publication year 2002
Pages 2295-2312
Availability location كلية الزراعة بمشتهر
Availability number
Organization Name
Country Egypt
City مشتهر - بنها
Publisher Name: كلية الزراعة بمشتهر - جامعة بنها
serial title Annals Of Agricultural Science, Moshtohor
ISSN 1110-0419
Volume 40 . 4
Department Field Drainage Research
Author(s) from ARC
Agris Categories Soil chemistry and physics
AGROVOC
TERMS		 Adsorption. Calcium. Clay minerals. Desorption. Potassium. Soil chemistry.
Publication Type Journal
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