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Gaseous Diffusion Evaluation in Forest Humus
Author(s) -
Ballard T. M.
Publication year - 1970
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1970.03615995003400030046x
Subject(s) - humus , diffusion , porosity , soil science , anisotropy , chemistry , environmental science , soil water , thermodynamics , physics , organic chemistry , optics
Penman's ratio of direct length to effective diffusion path length, L/L e , is not directly predictable from the air content of forest humus, probably because of anisotropic pore orientation. The diffusion coefficient of a gas in the unsaturated porous medium can be estimated from temperature, air pressure, porosity, water content, and an empirically determined value of L/L e . A steady state CO 2 diffusion method is proposed for measuring L/L e and gaseous diffusion coefficient in either loose or structurally intact forest humus samples.