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 Bouma, J. Search for Related Content PubMed Articles by Bouma, J. Agricola Articles by Bouma, J.

Use of Physical Methods to Expand Soil Survey Interpretations of Soil Drainage Conditions¹

ABSTRACT

Classification systems of soil drainage conditions are used in the soil survey program to characterize hydrodynamics of soils in the field and these data are used for soil survey interpretations. Estimates of soil permeability and internal soil drainage, based mainly on inferences made from morphological features, and an estimate of runoff are used in the Soil Survey Manual to determine the placement of a soil in one of seven drainage classes. Different soil moisture regimes are defined in the new soil taxonomic system in terms of measurements made in situ. These methods do not provide the quantitative data needed for predicting what soil behavior will be under environmental conditions that have changed temporarily or permanently. Complex numerical procedures and simple approximate physical methods, both requiring hydraulic conductivity and moisture retention data, can be used to calculate hydrodynamic soil behavior for a variety of simplified boundary conditions. Two approximate methods were applied to four Wisconsin soils in which measurements of hydraulic conductivity had been made in situ. This work revealed that two soils that had been placed previously in different drainage classes on the basis of differences in soil mottling, actually had comparable hydrologic properties.

¹ Contribution from the Wisconsin Geol. and Nat. Hist. Surv., Univ. Ext., Univ. of Wis. and the Soil Sci. Dep., Univ. of Wisconsin, Madison. Field work was funded in part by the Wis. Dep. of Nat. Resour. Published with the permission of the Director of the Wis. Geol. and Nat. Hist. Surv. and the Director of the Agr. Exp. Sta.

² Assistant Professor of Soil Science, Univ. of Wisconsin, Madison 53706. The author is indebted to P. A. C. Raats and F. D. Hole for helpful suggestions.

Received for publication July 24, 1972. Accepted for publication January 29, 1973.