An alternative index to ESP to explain dispersion occurring in Australian soils when Na content is low

Marchuk, A. and Marchuk, S. and Bennett, J. and Eyres, M. and Scott, E. (2014) An alternative index to ESP to explain dispersion occurring in Australian soils when Na content is low. In: National Soil Science Conference (NSS 2014): Securing Australia's Soils - for Profitable Industries and Healthy Landscapes, 23-27 Nov 2014, Melbourne, Australia.

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Re-use of industrial and agricultural wastewater for irrigation can increase the concentration of potassium in
soil and affect soil structure. However, investigations of clay dispersion have traditionally focused on soils with high exchangeable sodium, therefore exchangeable sodium percentage (ESP) has been used to assess soil structural stability. Currently, Australian soils have been considered non-sodic or non-dispersive when the soil ESP <6. However, a few studies have demonstrated that potassium (K) ions in the exchange complex of soil can also assist clay dispersion even when the exchangeable sodium (Na) levels are minimal.
The dispersion (as turbidity) and ESP were measured on 74 Australian soils. 17 of those soils showed a considerable level of dispersion, despite ESP <4.5. In all of these soils the Na to K ratio was <1. The relationships between ESP and turbidity were poor (R2= 0.23) indicating limitations of using the ESP for identifying potentially dispersive soils when K is present on the soil exchange sites. Therefore, we used exchangeable cation ratio (ECR), as an index alternative to ESP, but which takes into account effects of exchangeable K on clay dispersion. The good correlation obtained between ECR and the parameters like turbidity and zeta potential support its use in assessing soil structural stability when the appreciable amount of K present on exchange sites.

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Item Type: Conference or Workshop Item (Commonwealth Reporting Category E) (Poster)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2014 Soil Science Australia. This publication is copyright. It may be reproduced in whole or in part for the purposes of study, research, or review, but is subject to the inclusion of an acknowledgment of the source. Presented poster.
Faculty/School / Institute/Centre: Current - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying
Date Deposited: 10 Apr 2015 04:02
Last Modified: 13 Jun 2017 00:52
Uncontrolled Keywords: ESP; clay dispersion; ECR; soil structure
Fields of Research : 05 Environmental Sciences > 0503 Soil Sciences > 050304 Soil Chemistry (excl. Carbon Sequestration Science)
05 Environmental Sciences > 0502 Environmental Science and Management > 050207 Environmental Rehabilitation (excl. Bioremediation)
07 Agricultural and Veterinary Sciences > 0799 Other Agricultural and Veterinary Sciences > 079901 Agricultural Hydrology (Drainage, Flooding, Irrigation, Quality, etc.)
Socio-Economic Objective: D Environment > 96 Environment > 9614 Soils > 961402 Farmland, Arable Cropland and Permanent Cropland Soils

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