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 Grossman, R. B. Articles by Cline, M. G. Search for Related Content PubMed Articles by Grossman, R. B. Articles by Cline, M. G. Agricola Articles by Grossman, R. B. Articles by Cline, M. G.

Relationships between Rigidity and Particle Size Distribution¹

ABSTRACT

Twenty-four fragipan horizons were studied to determine the relationships between rigidity and particle size distribution. Objective consistence measurements, using relatively unaltered clods, were related to various textural components. Fourteen of the horizons were relatively sandy (sandy loams and light loams) and 10 were silty (silt loams).

The measurement of consistence involved: (1) shaping clods by hand into rough cylinders approximately 40 mm. long and 25 mm. in diameter; (2) encasing the upper and lower surfaces of each clod in plaster of paris to form smooth, parallel bearing surfaces; and (3) crushing the clods by the slow application of an axial stress and recording the maximum stress withstood per unit of crosssectional area over which the stress was applied. Mean values of 25 to 40 clods from each horizon were used in analyses of the data.

Rigidity was found to be highly correlated with percent total clay. It was concluded that clay was a principle bonding agent among primary particles, that very fine sand or silt may be equally effective as a matrix within which such clay bonding may occur, and that clay may act either as a bonding agent or as an agent of structural development and consequent weakness, depending upon its amount and distribution within the soil mass. The data do not suggest a special role for ultra-fine clay.

¹ A contribution of the Department of Agronomy, New York State College of Agriculture, Cornell University, Ithaca, N. Y., as Agronomy Paper No. 406. A portion of a thesis submitted in partial fulfillment of the requirements for the M.S. degree in the Graduate School, Cornell University, Ithaca, N. Y.

² Graduate Assistant and Professor of Soil Science, respectively. Department of Agronomy, Cornell University, Ithaca, N. Y. Senior author now a Research Assistant, Department of Agronomy, University of Illinois, Urbana.

Received for publication March 13, 1956. Accepted for publication March 1, 1957.