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The Distribution of Sodic Soils in Tasmania

Citation

Doyle, RB and Habraken, FM, The Distribution of Sodic Soils in Tasmania, Australian Journal of Soil Research, 31 pp. 931-47. ISSN 0004-9573 (1993) [Refereed Article]

DOI: doi:10.1071/SR9930931

Abstract

It is estimated that sodic soils (ESP>6) occupy at least 23% of Tasmania’s land area based on the present limited soil data set. Sodic soils are mostly restricted to lower rainfall areas (<800 mm/y) of eastern Tasmania, occurring primarily in the Launceston Tertiary Basin, the Derwent, Coal, Jordan and Huon River Valleys and on Flinders Island. In Tasmania, sodic soils have formed predominantly from Triassic and Permian mudstones and sandstones, Tertiary clays and unconsolidated Quaternary deposits. However, profiles with sodic features have also developed above granite, Jurassic dolerite and Tertiary basalt. Sodic soils most commonly occur on lowland plains, river terraces and in valley floors. In Tasmania, sodic soils are characterized morphologically by: abrupt separation of a sandy, bleached A2 horizon from a moderately sodic (ESP 6-15) clay subsoil; coarse prismatic, columnar and/or angular blocky pedality in the subsoil, which may exhibit vertic properties; hardsetting sandy A2 horizons in some profile classes; fine sandy crack infills and clay-organic coatings on ped faces in the upper B2 horizon; and thick, sticky and greasy fine clay argillans on ped faces, and clay infills in cracks and other voids in the lower B2 horizon that contribute to reduced porosity and permeability. Sodic soils in Tasmania have traditionally been utilized for pasture production with occasional cultivation for fodder crops and pasture renewal. Under a pastoral system, few sodicity problems have been recognized as such. However, in the last 10 years there has been increased cropping, particularly for poppies and more recently potatoes. Soil structure decline and drainage problems have become key factors limiting production. Management problems are mainly due to poor internal and external drainage, with poor structure in the A2 horizons which liquefy in winter and often set hard in summer. Salinity in associated drainage depressions is a problem gaining increasing recognition. © 1993, CSIRO. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Environmental Sciences
Research Group:Soil Sciences
Research Field:Land Capability and Soil Degradation
Objective Division:Animal Production and Animal Primary Products
Objective Group:Other Animal Production and Animal Primary Products
Objective Field:Animal Production and Animal Primary Products not elsewhere classified
Author:Doyle, RB (Dr Richard Doyle)
ID Code:26435
Year Published:1993
Web of Science® Times Cited:6
Deposited By:Agricultural Science
Deposited On:2003-07-07
Last Modified:2003-07-07
Downloads:0

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