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 Hanks, R. J. Search for Related Content PubMed Articles by Hanks, R. J. Agricola Articles by Hanks, R. J.

Water Vapor Transfer in Dry Soil¹

ABSTRACT

Water vapor transfer in three dry soils was measured. The influence of porosity and depth of dry soil was investigated. Measurements were made primarily under isothermal conditions. Some measurements were made on one soil under nonisothermal conditions where the samples were radiated with a heat lamp. Liquid water movement was eliminated as a factor by treating the soil with a chemical water repellent.

Calculations of water vapor transfer based on simple diffusion were made. The ratio of measured to calculated values was 1.38 for the Ladysmith silty clay loam, 1.32 for the Geary silt loam, and 1.04 for the Sarpy fine sandy loam. Porosity and depth of dry soil had no measurable influence on the ratio of measured to calculated values. This suggests that diffusion is the primary process involved.

The ratio of the measured to calculated values for the Geary silt loam was 1.23 for the radiated samples. This is slightly less than the ratio measured for isothermal conditions which, considering the errors involved, indicates that simple diffusion theory is approximately correct for water vapor transfer in dry soil under both isothermal and nonisothermal conditions.

¹ Contribution from the Agricultural Research Service, USDA and Kansas Agricultural Experiment Station, Manhattan, cooperating. Contribution No. 600, Department of Agronomy.

² Soil Scientist (Physics). Western Soil and Water Management Research Branch, ARS, USDA.

Received for publication December 13, 1957. Accepted for publication June 2, 1958.