HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Bower, C. A. Articles by Goertzen, J. O. Search for Related Content PubMed Articles by Bower, C. A. Articles by Goertzen, J. O. Agricola Articles by Bower, C. A. Articles by Goertzen, J. O.

Negative Adsorption of Salts by Soils¹

ABSTRACT

Samples of Ca- and Na-saturated soils were adjusted to the saturation moisture percentage with chloride salt solutions having concentrations of approximately 10, 100, and 1000 me./l. After equilibration, successive fractions of the soil solutions consisting of that removed between suctions of 0 to 1, 1 to 4, 4 to 8, and 8 to 16 atmospheres were obtained by the use of a pressure-membrane apparatus. Chemical analyses of these fractions and determinations of the Cl concentrations of the solutions remaining in the soils after extraction at 16 atmospheres of suction showed pronounced gradients in the salt concentrations of soil solutions, the solution retained at the higher suctions having lower concentrations. The concentration gradient was considerably greater for Na-saturated than for Ca-saturated soil except at the highest salt level employed.

The negative adsorption of various salts by soils was determined quantitatively from surface area measurements by ethylene glycol retention and from the difference between the true amount of salt present and that indicated by analysis of a saturation extract obtained at a suction of about one-half atmosphere. For three Ca-saturated soils the negative adsorption of CaCl₂ was nearly the same at equivalent concentrations in the saturation extract, the values at concentrations of 10, 100, and 1000 me./l. being about 5x10^-6, 35x10^-6, and 290x10^-6 me./sq.m., respectively. The negative adsorption of NaCl and Na₂SO₄ by Na-saturated soils was similar to but greater than that of CaCl₂ by Ca-saturated soils at equivalent concentrations in the saturation extract.

¹ Contribution from the U. S. Salinity Laboratory, S.W.C.R.B., A.R.S., U.S.D.A., Riverside, Calif., in cooperation with the 17 Western States and the Territory of Hawaii. Presented before Div. II, Soil Science Society of America, St. Paul, Minn., Nov. 11, 1954.

² Soil Scientist and Chemist, respectively.

Received for publication October 17, 1954.