Publication Date
12-2024
Series Number
427
Publisher
Department of Primary Industries and Regional Development
City
Perth
ISSN
1039-7205
Abstract
The aim of the Western Australian soil groups (WA soil groups) is to classify soils of Western Australia into a limited set using criteria that are easy to recognise in the field. It is a general-purpose classification with a focus on agronomic and rangeland grazing potential. The WA soil groups are designed for WA needs. It complements the Australian Soil Classification (ASC) by grouping the continuum of soils into a limited set of soil types, which simplifies soil variability for generalists, allows soil surveyors to create standardised soil-type legends for mapping products and permits further analyses of spatial data for land evaluation. The WA soil groups are each assigned a ‘closest matching ASC’ in the WA digital soil information system to introduce a generalist audience to the official Australian soil classification without needing to understand technical details.
This report documents the WA soil groups and the procedure used to classify them, and provides:
- a method to identify soils using soil morphology information from field investigations
- standardised common names for soils of WA
- a standardised and definitive classification for statewide soil observations and soil mapping data.
Central to this report is a diagnostic key to distinguish profiles into one of 12 soil supergroups and then into one of 155 soil groups. The key is an instruction set that must be followed sequentially, from the top down. Soil features that act as classification criteria in the key are stratified by fixed depth increments deemed important to the growth of annual and perennial crop roots. These criteria are explicit, being either present, absent or not diagnostic. Each criterion within the key is explicitly defined to help with classification. The combination of soil features present or absent makes the key definitive – every adequately described soil can be classified and named.
This fifth edition includes major changes and extra detail. The suite of classes available now encompass the complete range of soils found throughout WA. Previous editions listed common soils relevant for the rain-fed and irrigated agricultural land in the south-west without explicitly defining all aspects of their morphology. The addition of numerous calcareous soils and shallow soils broadens the utility of the classification to rangelands and the arid interior. The expansion of classes of ironstone gravel soils better distinguishes these soils across south-west WA. Changes in this edition improve alignment with the ASC.
An accompanying report (Resource management technical report 430) is being prepared to assist users of the diagnostic key by providing additional information to cross-reference the soil identification using visual aids, descriptive text, location maps and soil management information.
Number of Pages
67
Keywords
soil, soil groups, soil classification, diagnostic key, Western Australia
Disciplines
Agriculture | Environmental Education | Environmental Monitoring | Natural Resources and Conservation | Natural Resources Management and Policy | Soil Science
Recommended Citation
Galloway P, van Gool D, Stuart-Street A, Griffin E, Pathan S and Schoknecht N (2024) ‘Western Australian soil groups: a diagnostic key to identify soils in Western Australia’, 5th edition, Resource management technical report 427, Department of Primary Industries and Regional Development, Western Australian Government.
Maps
Maps are not included as part of the complete document download. If this report contains a map, it will be available in the individual parts list below.
Included in
Agriculture Commons, Environmental Education Commons, Environmental Monitoring Commons, Natural Resources and Conservation Commons, Natural Resources Management and Policy Commons, Soil Science Commons
Comments
This publication supersedes the previous 4 editions of 'Soil groups of Western Australia: a simple guide to the main soils of Western Australia' (Resource management technical reports 171, 193, 246 and 380).
This fifth edition is a major refinement and expansion of the WA soil groups. It retains the 12 soil supergroups of earlier editions, but the number of soil groups has increased from 61 to 155.
Two main reasons justify the expansion. Firstly, this edition of the classification is relevant to soils of the entire state, whereas earlier editions focused on soils of the south-west dryland agriculture zone. Secondly, this edition updates classification criteria and background information, so the classification is now explicit, comprehensive and consistent.