A Note on a Method for the Estimation of Exchangeable Bases in Black Soils Containing Free Calcium Carbonate and Soluble Salts Including Gypsum

Abstract

There are several methods for the estimation of exchangeable bases in soils. All of them are satisfactory for normal non-calcareous soils When the soil contains free calcium carbonate none of the methods is quite good. But fairly accurate values can be obtained by Hissink's Sodium Chloride method and Kelly's alcoholic potassium chloride method provided the soil contains a fair amount of free-calcium carbonate (i. e, more than a sufficient amount of calcium carbonate in 25 grms. of the soil to saturate 2 litres of the leaching solution). These methods also fail, however, when the soil contains soluble salts such as chlorides and sulphates. In the case of soils containing free calcium carbonate and soluble salts no satisfactory method is available for the estimation of exchangeable bases. The idea that would strike one immediately would be to wash out the soluble salts and then to estimate the exchangeable bases by Hissink's or Kelly's method There are, however, many practical and theoretical considerations which prevent this idea being adopted. First of all during the removal of the soluble salts by washing with water, changes are brought about in the exchange complex of the soil which would vitiate the procedure. On the practical side it is found that even before the major portion of the soluble salts are washed out the soil becomes dispersed and passes through the filter.

DOI

https://doi.org/10.29321/MAJ.10.002370

Pages

43 - 46

Creative Commons

Copyright

© The Author(s), 2026. Published by Madras Agricultural Students' Union in Madras Agricultural Journal (MAJ). This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited by the user.

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