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 Kittrick, J. A. Articles by Jackson, M. L. Search for Related Content PubMed Articles by Kittrick, J. A. Articles by Jackson, M. L. Agricola Articles by Kittrick, J. A. Articles by Jackson, M. L.

Rate of Phosphate Reaction with Soil Minerals and Electron Microscope Observations on the Reaction Mechanism¹

ABSTRACT

The phosphate reaction rate for several soils was found to be very rapid initially, but diminished to lower values in a matter of minutes. For example, the rate of phosphate reaction with a Catalina Latosol after 3 minutes contact was 100 tons of superphosphate per acre per hour but after 1 month the rate of reaction had fallen to about 1 pound per acre per hour. Removal of extractable iron oxides from the Catalina soil greatly diminished the rate of reaction of phosphate with the soil but reaction with the kaolinite portion was nearly half of the total. It was possible to produce colloidal iron oxide and aluminum hydroxide particles analogous to the reactive surfaces responsible for the rapid initial reaction of phosphate with soil minerals. Electron microscope observations of these minerals in contact with phosphate solution disclosed the formation in a few minutes of separate-phase phosphate crystals by the mechanism of solution-precipitation. These experiments suggest that the solution-precipitation mechanism is important in phosphate fixation in soils.

¹ This work was supported in part by the University Research Committee through a grant of funds from the Wisconsin Alumni Research Foundation. Presented before Div. II, Soil Science Society of America, St. Paul, Minn., Nov. 9, 1954.

² Research Assistant and Professor of Soils, respectively.

Received for publication October 17, 1954.