The impact of clay dispersion and migration on soil hydraulic conductivity and pore networks

Awedat, Awedat Musbah and Zhu, Yingcan ORCID: https://orcid.org/0000-0003-4087-0169 and Bennett, John McLean and Raine, Steven R. (2021) The impact of clay dispersion and migration on soil hydraulic conductivity and pore networks. Geoderma, 404:115297. pp. 1-12. ISSN 0016-7061


Abstract

Using saline and sodic waters for irrigating agricultural lands has increased worldwide, which may cause adverse effects on soil porosity, structural stability and permeability. However, few studies have investigated the effect of clay swelling, dispersion and migration on the reduction of saturated hydraulic conductivity (Ksat) by analysing the total porosity and pore size change through the profile. In this study, two soils with contrasting mineralogy was used and packed at two different bulk densities (1.0 and 1.2 g cm−3). Soil columns were leached with three types of sodium adsorption ratio (SAR) solutions, i.e. good quality water (GQW), SAR 10 and SAR 50 solutions, before distilled water (low ionic strength) was leached through. The results indicated that the application of distilled water decreased Ksat for all soils, particularly in the initially sodic water treated columns. The Ksat of leaching with distilled water in low density columns were generally higher, but showed more degree of reduction than more compacted columns, mainly related to the high initial porosity and macropores that enabled dispersed clay to move through the soil column and out in the leachate. The application of distilled water significantly reduced the proportion of macro and mesopores, whereas increased the proportion of micropores in both soils, particularly for soil columns initially treated high SAR solutions. When the dispersed clay was trapped within the column, the depth of clay accumulation was affected by a combined effect of packing density, soil type and water quality.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Sustainable Agricultural Systems (1 Aug 2018 -)
Date Deposited: 07 Mar 2022 04:43
Last Modified: 07 Mar 2022 04:43
Uncontrolled Keywords: saturated hydraulic conductivity (Ksat), clay dispersion, clay migration, soil compaction, water quality
Fields of Research (2008): 05 Environmental Sciences > 0503 Soil Sciences > 050304 Soil Chemistry (excl. Carbon Sequestration Science)
05 Environmental Sciences > 0503 Soil Sciences > 050305 Soil Physics
05 Environmental Sciences > 0503 Soil Sciences > 050302 Land Capability and Soil Degradation
Fields of Research (2020): 30 AGRICULTURAL, VETERINARY AND FOOD SCIENCES > 3002 Agriculture, land and farm management > 300299 Agriculture, land and farm management not elsewhere classified
30 AGRICULTURAL, VETERINARY AND FOOD SCIENCES > 3002 Agriculture, land and farm management > 300210 Sustainable agricultural development
Socio-Economic Objectives (2008): D Environment > 96 Environment > 9614 Soils > 961402 Farmland, Arable Cropland and Permanent Cropland Soils
Socio-Economic Objectives (2020): 18 ENVIRONMENTAL MANAGEMENT > 1806 Terrestrial systems and management > 180605 Soils
Funding Details:
Identification Number or DOI: https://doi.org/10.1016/j.geoderma.2021.115297
URI: http://eprints.usq.edu.au/id/eprint/47024

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