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 Mehuys, G. R. Articles by Weeks, L. V. Search for Related Content PubMed Articles by Mehuys, G. R. Articles by Weeks, L. V. Agricola Articles by Mehuys, G. R. Articles by Weeks, L. V.

Effect of Stones on the Hydraulic Conductivity of Relatively Dry Desert Soils¹

ABSTRACT

The objective of this study was to determine whether moisture transmission properties of stony soils could be evaluated using samples of the same soil in which the stony fraction (> 2 mm) had been excluded. Experiments were conducted in the laboratory on soil columns with and without stones. Unsaturated hydraulic conductivity (K) was measured with a transient outflow method over the matric potential range of –0.05 to –50 bars using tensiometers and soil psychrometers. The soils studied were Rock Valley gravelly loamy sand (Mojave Desert, Nevada) and Tubac and Rillito gravelly sandy loams (Sonoran Desert, Arizona). On a weight basis, these soils contain up to 40% stones > 2 mm in diameter.

If expressed as a function of matric potential, hydraulic conductivity values were similar, with or without stones. Soil water potential as measured by tensiometers or by thermocouple psychrometers is not affected by stones because these instruments respond to moisture changes in the soil portion only. When K was expressed as a function of volumetric water content, the apparent conductivities were higher for a given water content when stones were present. A simple correction of water contents of stone-free samples, based on the stone volume of each soil, adequately accounted for differenecs observed when water contents were computed on a total volume basis.

¹ Contribution of the Department of Soil Sci. & Agr. Eng., Univ. of Calif., Riverside 92502. This work was supported in part by funds from the National Science Foundation under IBP Desert Biome, Utah State Univ., Ecology Center, Subcontract no. 539. Presented before Div. S-1, Soil Science Society of America meetings, 14 Nov. 1973, Las Vegas, Nev.

² Former Research Assistant, Professors of Soil Physics, and Staff Research Associate, respectively. Senior author is now Research Scientist, Canada Agriculture, 2560 Chemin Gomin, Ste-Foy, Quebec G1V 2J3, Canada.

Received for publication May 1, 1974. Accepted for publication October 18, 1974.