Threshold electrolyte concentration for dispersive soils in relation to CROSS
Poster
Paper/Presentation Title | Threshold electrolyte concentration for dispersive soils in relation to CROSS |
---|---|
Presentation Type | Poster |
Authors | Marchuk, Alla (Author), Rengasamy, Pichu (Author) and McNeill, Ann (Author) |
Editors | Birkett, L. L. and Sparrow, L. A. |
Journal or Proceedings Title | Proceedings of the 5th Joint Australian and New Zealand Soil Science Conference (SSA 2012) |
ERA Conference ID | 50979 |
Number of Pages | 4 |
Year | 2012 |
Place of Publication | Melbourne, Australia |
ISBN | 9780646591421 |
Web Address (URL) of Paper | http://www.soilscience2012.com |
Conference/Event | 5th Joint Australian and New Zealand Soil Science Conference (SSA 2012): Soil Solutions for Diverse Landscapes |
Joint Australian and New Zealand Soil Science Conference | |
Event Details | 5th Joint Australian and New Zealand Soil Science Conference (SSA 2012): Soil Solutions for Diverse Landscapes Parent Joint Australian and New Zealand Soil Science Conference Event Date 02 to end of 07 Dec 2012 Event Location Hobart, Australia |
Event Details | Joint Australian and New Zealand Soil Science Conference |
Abstract | Sodium salts tend to dominate salt-affected soils and groundwater in Australia; therefore, sodium adsorption ratio (SAR) is used to parameterise soil sodicity and the effects of sodium on soil structure. However, some natural soils in Australia, and others irrigated with recycled water, have elevated concentrations of potassium and/or magnesium. Therefore, there is a need to derive and define a new ratio including these cations in place of SAR, which will indicate the dispersive effects of Na and K on clay dispersion, and Ca and Mg on flocculation. Based on the differential dispersive effects Na and K and the differential flocculation powers of Ca and Mg, we propose the concept of 'cation ratio of soil structural stability' (CROSS), analogous to SAR. This paper also gives the results of a preliminary experiment conducted on three soils varying in soil texture on hydraulic conductivity using percolating waters containing different proportions of the cations Ca, Mg, K, and Na. The relative changes in hydraulic conductivity of these soils, compared with the control treatment using CaCl2 solution, was highly correlated with CROSS. Clay dispersion in 29 soils treated with irrigation waters of varying cationic composition was highly correlated with CROSS rather than SAR. It was also found that CROSS measured in 1:5 soil/water extracts was strongly related to the ratio of exchangeable cations. These results encourage further study to investigate the use of CROSS as an index of soil structural stability in soils with different electrolytes, organic matter, mineralogy, and pH. |
Keywords | exchangeable magnesium; exchangeable potassium; irrigation; sodicity; soil structure |
ANZSRC Field of Research 2020 | 401199. Environmental engineering not elsewhere classified |
410604. Soil chemistry and soil carbon sequestration (excl. carbon sequestration science) | |
300201. Agricultural hydrology | |
Public Notes | No evidence of copyright restrictions preventing deposit. |
Byline Affiliations | University of Adelaide |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q2971/threshold-electrolyte-concentration-for-dispersive-soils-in-relation-to-cross
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