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THE VOLUME AND POROSITY OF SOIL CRUMBS
Author(s) -
CURRIE J. A.
Publication year - 1966
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1966.tb01449.x
Subject(s) - porosity , kerosene , volume (thermodynamics) , displacement (psychology) , materials science , soil water , geotechnical engineering , mineralogy , soil science , environmental science , composite material , geology , chemistry , physics , psychology , organic chemistry , quantum mechanics , psychotherapist
Summary A simple and inexpensive apparatus (a test‐tube, burette, and pin) is described for measuring volumes by liquid displacement to an accuracy of greater than 0.5 per cent. This has been adapted to measure soil crumb porosities, ε c , by saturating 3–4 g samples of crumbs with kerosene, measuring the weight of kerosene retained internally, then measuring their volume by displacement. Three estimates of crumb porosity from these measurements are compared. Experimental values range from ε c = 0.205 for the headland of an arable field to ε c = 0.351 for a permanent pasture. Crumb porosity is proposed as a measure of structural status for soils because it assesses the degree to which soil management has succeeded in holding the constituent primary particles apart from the positions of inherent closest packing that they would ultimately assume in an unstable soil. By comparison, the inter‐crumb porosity, ε v , can be used as a measure of cultivation status. In the form expressed, these two porosities are related to the more frequently encountered total porosity ε t by the relation