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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Olsen, S. R. Articles by Watanabe, F. S. Search for Related Content PubMed Articles by Olsen, S. R. Articles by Watanabe, F. S. Agricola Articles by Olsen, S. R. Articles by Watanabe, F. S.

A Method to Determine a Phosphorus Adsorption Maximum of Soils as Measured by the Langmuir Isotherm¹

ABSTRACT

Adsorption of phosphorus by soils from dilute solutions showed a closer agreement with the Langmuir isotherm than with the Freundlich isotherm. Constants calculated from the Langmuir isotherm and interpretations based upon the meaning of these constants permit a sound theoretical approach to some of the problems of phosphorus retention in soils.

The adsorption maximum claculated from the Langmuir isotherm was closely correlated with the surface area of soils as measured by ethylene glycol retention. The correlation coefficients and regression equations were r = 0.98 and y = 0.276x + 3.47 for 10 alkaline soils, and r = 0.96 and y = 0.641x + 5.73 for 12 acid soils, where y = mg. P per 100 g. soil and x = mg. ethylene glycol retained per g. of soil. For a given surface area, i.e., 30 mg. glycol per g. soil, the acid soils held 2.17 times as much phosphorus as the alkaline soils.

The average values of a second constant, k, derived from the slope and intercept values, were 0.92 and 4.39 for the alkaline and acid soils, respectively. As the value of this constant increases, the bonding energy of the soil for phosphorus increases. Thus, the acid soils retained more phosphorus per unit of surface area and also held the phosphorus with a greater bonding energy than the alkaline soils

¹ This work was conducted in cooperation with the Colorado Agr. Exp. Sta. Approved by the Director of the Colorado Agr. Exp. Sta. as Scientific Journal Series No. 465. Presented before Div. II., Soil Science Society of America, Davis, Calif., Aug. 17, 1955.

² Soil Scientists, Soil and Water Conservation Research Branch. A.R.S., U.S.D.A., Colorado A. & M. College, Fort Collins, Col.

The authors wish to acknowledge the help of Dr. B. N. Rolfe, Water Resources Division, U. S. Geological Survey, for his interpretation of the X-ray diffraction patterns and use of equipment. The authors are indebted to Drs. L. A. Dean and C. V. Cole for suggestions and encouragement in planning the experimental work and preparing this manuscript.

Received for publication April 19, 1956. Accepted for publication June 13, 1956.

This article has been cited by other articles:

				T. Wood, T. WOOD, F. H. BORMANN, and G. K. VOIGT Phosphorus Cycling in a Northern Hardwood Forest: Biological and Chemical Control Science, January 27, 1984; 223(4634): 391 - 393. [Abstract] [PDF]