The Drying of Soil: Thermal Regimes and Ambient Pressures

Cary, J.W. (1967) The Drying of Soil: Thermal Regimes and Ambient Pressures. Agricultural Meteorology. 4:353-365.

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Abstract

Evaporation from a loam soil was studied in the laboratory during the falling-rate
stage of drying. The primary variables were temperatures regimes and ambient
pressures. The data suggested that: (a) there is a significant relation between the
soil temperature and the vapor pressure of water in the air above the surface; (b) the
water vapor transfer through the dry layer at the surface is accomplished in part
by viscous air flow; (c) diurnal thermal gradients may cause a significant movement
of water near the soil surface during the falling-rate stage of drying. Consequently,
the conclusion follows that the isothermal "soil-moisture diffusion theory" cannot
be expected to describe drying during time intervals of less than 24 hours. Because
of the periodic nature of the thermally induced transfer phenomena, the "diffusion
theory" will give curves which approximate cumulative drying over long time periods,
though such relations must be considered as semi-empirical.

Item Type:	Article
NWISRL Publication Number:	0078
Subjects:	Soil Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:53
Last Modified:	15 Mar 2017 22:16
Item ID:	590
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/590