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 33:75-81 (1969)
© 1969 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 Schnitzer, M.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Schnitzer, M.
Agricola
Right arrow Articles by Schnitzer, M.

Reactions between Fulvic Acid, a Soil Humic Compound and Inorganic Soil Constituents1

M. Schnitzer2

ABSTRACT

The order of stabilities at pH 5.0 of complexes formed between a water-soluble Podzol fulvic acid and nine divalent metal ions was Cu > Pb > Fe > Ni > Mn > Co > Ca > Zn > Mg. Log K (stability constant) values ranged from 8.69 for the Cu-complex to 2.09 for the Mg-complex and were higher at pH 5.0 than at pH 3.5. The Irving-Williams series was not followed. Provisional results indicated that log K values for Fe3+- and Al3+-fulvic acid complexes were higher than those for divalent metal-fulvic acid complexes. Two types of reactions occurred between fulvic acid and metal ions and hydrous oxides: a major one in which both COOH and phenolic OH groups reacted simultaneously, and a minor one involving less acidic COOH groups only. To develop analytical methods for investigating metal-organic matter complexes occurring in soils, model compounds, containing varying metal to fulvic acid ratios, were prepared. The methods so developed were later used as diagnostic tools for the characterization of metal-organic matter complexes extracted from natural soils or occurring as distinct horizons in soil profiles.

In contrast to unreacted fulvic acid, metal fulvic acid complexes reacted with phosphate via the metal to form fulvic acidmetal-phosphate. The interlamellar adsorption of fulvic acid by montmorillonite depended on the pH of the medium, the fulvic acid concentration and the type of cation with which the clay was saturated. Fulvic acid was found to have a positive effect on root initiation, which appeared to be related to its metal complexing ability.

NOTES

Contribution no. 262, Soil Research Institute, Canada Department of Agriculture, Ottawa, Ontario. Presented at a symposium—Metal Chelation in Soils—Div. S-2, Soil Science Society of America, Washington, D.C., Nov. 8, 1967.

2 Senior Research Scientist. The author thanks S. I. M. Skinner, J. G. Desjardins, I. Hoffman, J. A. McKeague, M. Levesque, H. Kodama, and P. A. Poapst for their collaboration in the various phases of this work.

Received for publication February 15, 1968. Accepted for publication June 3, 1968.






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 © 1969 by the Soil Science Society of America.