SSSAJ Grow Your Career with SSSA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published in Soil Sci Soc Am J 27:614-619 (1963)
© 1963 Soil Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Moreno, E. C.
Right arrow Articles by Osborn, G.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Moreno, E. C.
Right arrow Articles by Osborn, G.
Agricola
Right arrow Articles by Moreno, E. C.
Right arrow Articles by Osborn, G.

Solubility of Gypsum and Dicalcium Phosphate Dihydrate in the System CaO-P2O5-SO3-H2)O and in Soils1

E. C. Moreno and G. Osborn2

ABSTRACT

The solubility isotherm (25°C.) for gypsum was determined in the concentration range from 1.5 x 10-2 to 6.0 x 10-2 mols of S per liter by equilibrating CaSO4 · 2H2O with H2SO4 solutions of varying concentrations. The solubility product of gypsum calculated from these data was 2.45 x 10-5. The effect of gypsum upon the solubility of dicalcium phosphate dihydrate (DCPD) was related to the pH. The percentage of calcium in solution which was derived from DCPD was 80% and 3% at pH 3.6 and 6.3, respectively. The data from exchange resin and solubility studies are consistent with a hypothesized complex in solution of the form Ca(H2PO4)+. Equilibrations of DCPD and gypsum in soil systems indicated that apparent supersaturation with respect to both salts was obtained at pH values above 5.8. This anomalous behavior was explained by the complexing of Ca by soluble organic matter. The research findings are discussed in the light of soil and fertilizer chemistry.

NOTES

1 Contribution from the Soils and Fertilizer Research Branch, Division of Agricultural Department, TVA, Wilson Dam, Ala. Presented at the annual meeting of the American Society of Agronomy, Cornell University, Ithaca, New York, August 20–23, 1962.

2 Formerly Research Chemist, TVA, now Research Associate, American Dental Association Research Div., National Bureau of Standards, Washington 25, D. C.; and Analytical Chemist, TVA, respectively.

Received for publication August 8, 1962. Accepted for publication April 17, 1963.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Crop Science
Journal of Natural Resources
and Life Sciences Education		 Vadose Zone Journal
Journal of Plant Registrations Journal of
Environmental Quality		 The Plant Genome
Copyright © 1963 by the Soil Science Society of America.