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 Bhumbla, D. R. Articles by McLean, E. O. Search for Related Content PubMed Articles by Bhumbla, D. R. Articles by McLean, E. O. Agricola Articles by Bhumbla, D. R. Articles by McLean, E. O.

Aluminum in Soils: VI. Changes in pH-Dependent Acidity, Cation-Exchange Capacity, and Extractable Aluminum with Additions of Lime to Acid Surface Soils¹

ABSTRACT

Surface soils differing in extractable aluminum and organic matter were limed at various rates, moist incubated, and analyzed for pH-dependent acidity by extracting KCl-leached soils with triethanolamine (TEA) buffered BaCl₂ solution-pH 8.2. The pH-dependent acidity decreased markedly with rate of liming. Aluminum was extracted with 1N KCl and with 1N NH₄OAc-pH 4.8 using varying amounts of solution and extraction times. Increased amounts of KCl solution removed more Al from unlimed soils, and the pH-dependent acidity decreased correspondingly. More Al was extracted with NH₄OAc-pH 4.8 than with KCl, and differences in pH-dependent acidity of limed and unlimed soils were relatively less pronounced, especially in soils high in soluble Al. Prolonged leaching with NH₄OAc-pH 4.8 reduced these differences more. Cation-exchange capacities (CEC) measured with NH₄OAc-pH 7 or with TEA buffered BaCl₂-pH 8.2 did not vary appreciably with rate of liming. In soils high in soluble Al, CEC measured by leaching with unbuffered salt solutions were much lower than those obtained with NH₄OAc, but increased markedly with liming. The data suggest that acidity measured in KCl-leached soils includes not only the weak acid H⁺ ions which become reactive or displaceable at higher pH, but also acidity related to organic-complexed Al or hydroxy-Al polymer.

¹ Published with the permission of the Director of the Ohio Agr. Exp. Sta. as Journal Article no. 85-63. Presented before Div. S-2 Soil Science Society of America, Ithaca, N. Y. Aug. 22, 1962. The results were used by the senior author in partial fulfillment of the requirements for the Ph.D. degree, The Ohio State University. Financial assistance from Basic, Incorporated, Cleveland, Ohio is gratefully acknowledged.

² Former Research Assistant (now Agricultural Chemist, Punjab Agricultural University) and Professor of Agronomy, respectively.

Received for publication October 23, 1964. Accepted for publication March 16, 1965.