Pedosphere 2(3): 255--264, 1992
ISSN 1002-0160/CN 32-1315/P
©1992 Soil Science Society of China
Published by Elsevier B.V. and Science Press
Adsorption of Potassium and Calcium Ions by Variable Charge Soils |
LI HONG-YAN, JI GUO-LIANG |
Institute of Soil Science. Academia Sinica, P.O. Box 821, Nanjing 210008 |
ABSTRACT |
Interactions of potassium and calcium ions with four typical variable charge soils in South China were examined by measuring pK-0.5pCa value with a potassium ion-selective electrode and a calcium ion-selective electrode, and pK value with a potassium ion-selective electrode. The results showed that adsorption of potassium and calcium ions increased with soil suspension pH, and the tendency of the pK-0.5pCa value changing with pH differed with respect to pH range and potassium to calcium ratio. Adsorption of equal amount of calcium and potassium ions led to release of an identical number of protons, suggesting similar adsorption characteristics of these two ions when adsorbed by variable charge soils. Compared with red soil, latosol and lateritic red soil had higher adsorption selectivities for calcium ion. |
Key Words: |
Citation: Li, H. Y. and Ji, G. L. 1992. Adsorption of Potassium and Calcium Ions by Variable Charge Soils. Pedosphere. 2(3): 255-264. |
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