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 Kemper, W. D. Articles by Nelson, S. Search for Related Content PubMed Articles by Kemper, W. D. Articles by Nelson, S. Agricola Articles by Kemper, W. D. Articles by Nelson, S.

Gas Displacement and Aggregate Stability of Soils¹

ABSTRACT

When surface soils are dry, O₂ and N₂ are adsorbed on the external mineral surfaces. In the process of wetting the soil, water molecules displace the adsorbed O₂ and N₂ molecules to the gas phase where they can be measured, as was done in this study. These gases, released from the adsorbed phase, join entrapped air in the gaseous phase as the primary factor disintegrating aggregates when soils are wet quickly. Adsorption of N₂ and O₂ occurs on surface soils during hot dry afternoons as the water molecules leave the surface. During cool nights, relative humidities commonly rise above 50%, allowing more strongly adsorbed H₂O molecules to displace adsorbed O₂ and N₂. Release of this adsorbed N₂ and O₂ causes aggregates wetted by immersion during hot afternoons to be less stable than aggregates of the same soil wetted in the morning.

¹ Contribution from the Snake River Conservation Research Center, USDA-ARS, Kimberly, Id, in cooperation with Brigham Young University, Provo, UT.

² Director and Technician, Snake River Conservation Research Center, Route 1, Box 186, Kimberly, Id, 83341 and Associate Professor, Brigham Young Univ., Provo, Ut, respectively.

Received for publication April 12, 1984. Accepted for publication September 13, 1984.