Pedosphere 3(2): 107--117, 1993
ISSN 1002-0160/CN 32-1315/P
©1993 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Titratable Acidity and Alkalinity of Red Soil Surfaces |
| SHAO ZONG-CHEN, HE QUN, WANG WEI-JUN |
| Institute of Soil Science, Academia Sinica, P.O. Box 821, Nanjing 210008 |
| ABSTRACT |
| The surfaces of red soils have an apparent amphotenc character, carrying titratable acidity and titratable alkalinity simultaneously. The titratable acidity arises from deprotonation of hydroxyl groups of hydrous oxide-type surfaces and dissociation of weak-acid functional groups of soil organic matter, while the titratable alkalinity is derived from release of hydroxyl groups of hydrous oxide-type surfaces. The titratable acidity and titratable alkalinity mainly depended on the composition and content of iron and aluminum oxides in the soils. The results showed that the titratable acidity and titratable alkalinity were in significantly positive correlation not only with the content of amorphous aluminum oxide(Alo) and iron oxide(Feo) extracted with acid ammonium oxalate solution, free iron ox-ide(Fed) extracted with sodium dithionite-citrate-bicarbonate (DCB) and clays, but also with the zero point of charge (ZPC) of the samples. Organic matter made an important contribution to the titratable acidity. |
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| Citation: Shao, Z. C., He, Q. and Wang, W. J. 1993. Titratable Acidity and Alkalinity of Red Soil Surfaces. Pedosphere. 3(2): 107-117. |
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