HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Zaher, H. Articles by Ouaki, B. Search for Related Content PubMed Articles by Zaher, H. Articles by Ouaki, B. Agricola Articles by Zaher, H. Articles by Ouaki, B. Related Collections Structure and Properties Soil Physics Pore-Scale Modeling Macroporous/Aggregated Media

Division S-1—Soil Physics

Modeling Aggregate Internal Pressure Evolution following Immersion to Quantify Mechanisms of Structural Stability

^a Division de l'Organisation, des Méthodes et de la Gestion Informatique Ministère de la Pêche Maritime, B.P. 476 Agdal, Rabat, Morocco
^b Dép. des Sols et de Génie Agroalimentaire, Univ. of Laval, QC, Canada G1K 7P4
^c Dép. Génie des Matériaux, Ecole Nationale de l‘Industrie Minérale, B.P. 753 Agdal, Rabat, Morocco

^* Corresponding author (jean.caron{at}sga.ulaval.ca).

Identification of the key components controlling aggregate stability is important in soil structure research. The deterioration of soil aggregates during rapid wetting has often been attributed to the swelling and internal pressure buildup resulting from the compression of entrapped air by the advancing wetting front. Organic matter is known to reduce the extent of slaking, but the different modes of action have not yet been quantified. The objective of the study was to use theoretical three-dimensional models to quantify the effect of paper sludge amendment on the key processes controlling internal pressure evolution. A clay loam and a silty-clay loam were incubated for a 2-wk period with different amounts and types of paper sludge. Aggregates were then selected, air dried, and then fixed to a hypodermic needle connected to a pressure transducer, and the whole system was immersed in distilled water while images and pressure evolution were recorded. For both soils, the maximum internal pressure was lower in the sludge-amended aggregates. From the models fitted to the observed data, it appears that the addition of paper sludge resulted in an increase of the potential at the wetting front and a decrease of the near saturated hydraulic conductivity. This result suggests that sludge addition reduces pressure buildup by reducing the rate of water entry, lowering the potential at the wetting front and reducing the hydraulic conductivity of the aggregate.

This article has been cited by other articles:

				Z. Hafida, J. Caron, and D. A. Angers Pore Occlusion by Sugars and Lipids as a Possible Mechanism of Aggregate Stability in Amended Soils Soil Sci. Soc. Am. J., October 29, 2007; 71(6): 1831 - 1839. [Abstract] [Full Text] [PDF]

				A. J.M. Smucker, E.-J. Park, J. Dorner, and R. Horn Soil Micropore Development and Contributions to Soluble Carbon Transport within Macroaggregates Vadose Zone J., May 17, 2007; 6(2): 282 - 290. [Abstract] [Full Text] [PDF]