Gas Displacement and Aggregate Stability of Soils

Kemper, W.D. and Rosenau, Russell and Nelson, Sheldon (1985) Gas Displacement and Aggregate Stability of Soils. Soil Science Society of America Journal. 49(1):25-28.

PDF 541.pdf Download (232kB)

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.

Item Type:	Article
NWISRL Publication Number:	0541
Subjects:	Soil Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:52
Last Modified:	13 Jan 2017 22:57
Item ID:	430
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/430