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 Richburg, J. S. Articles by Adams, F. Search for Related Content PubMed Articles by Richburg, J. S. Articles by Adams, F. Agricola Articles by Richburg, J. S. Articles by Adams, F.

Solubility and Hydrolysis of Aluminum in Soil Solutions and Saturated-paste Extracts¹

ABSTRACT

Three Coastal Plains soils that had exhibited different "critical" pH values for maximum cotton yields in field experiments were analyzed for Al solubility. Fertilized soil was used to verify critical pH by a root-growth experiment in a growthchamber and to obtain displaced soil solutions (-bar moisture) and water extracts from saturated pastes. Extracts were also obtained from saturated pastes made with 0.01M and 0.05M KCl and with 0.0033M and 0.0167M CaCl₂. Solutions were analyzed for pH, Ca, Mg, Mn, K, NH₄⁺, Al, and SO₄^2-; the remaining ions required for electrical neutrality were assumed to be Cl^- and NO₃^-. A computer program, involving successive iterations of numerous equilibrium equations, was used to solve for ion activities and ion-pair concentrations, including the Al-ion species of Al³⁺, AlOH²⁺, Al₆(OH)₁₅³⁺, and AlSO₄⁺. The ion-product of (Al³⁺) (OH^-)³ was considerably larger and much more pH-dependent with AlOH²⁺ as the hydrolytic product than with Al₆(OH)₁₅³⁺. Calculated (Al³⁺) values were much lower for polymeric hydrolysis than for monomeric hydrolysis.

¹ Contribution from Dept. of Agronomy and Soils, Auburn Univ., Auburn, Ala. These results are part of the senior author's M.S. thesis.

² Research Associate and Professor.

Received for publication December 5, 1969. Accepted for publication June 9, 1970.