The Australian soil classification

Differences between local systems of soil classification hinder the communication between pedologists from different countries. The FAO–UNESCO Soil Map of the World, as a fruit of world-wide collaboration between innumerable soil scientists, is recognised internationally. Ideally, pedologists should be able to match whole classes in their local systems to those in an international soil classification system. The Australian Soil Classification (ASC) system, created specifically for Australian soil, is widely used in Australia, and Australian pedologists wish to translate the orders they recognise into the FAO soil units when writing for readers elsewhere. We explored the feasibility of matching soil orders in the ASC to units in the FAO legend using a multivariate analysis. Twenty soil properties, variates, of 4927 profiles were estimated from their visible–near infrared reflectance (vis–NIR) spectra. We arranged the profiles in a Euclidean 20-dimensional orthogonal vector space defined by standardised variates. Class centroids were computed in that space, and the Euclidean distances between the centroids of the ASC orders and units in the FAO scheme were also computed. The shortest distance between a centroid of any ASC order and one of units in the FAO classification was treated as a best match. With only one exception the best matches were those that an experienced pedologist might expect. Second and third nearest neighbours in the vector space provided additional insight. We conclude that vis–NIR spectra represent sufficiently well the essential characters of the soil and so spectra could form the basis for the development of a universal soil classification system. In our case, we could assign with confidence the orders of the ASC to the units of the FAO scheme. A similar approach could be applied to link other national classification systems to one or other international systems of soil classification.

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Assessing the Australian Soil Classification using cladistic analysis

Soil Research ◽

10.1071/sr14323 ◽

2015 ◽

Vol 53 (7) ◽

pp. 772 ◽

Cited By ~ 5

Author(s):

Gregory P. L. Miltenyi ◽

Malte C. Ebach ◽

John Triantafilis

Keyword(s):

Cladistic Analysis ◽

Soil Classification ◽

Morphological Characters ◽

Natural Soil ◽

Diverse Range ◽

Natural Classification ◽

Confidence Levels ◽

Two Measures ◽

Australian Soil ◽

Made In

The Australian Soil Classification (ASC) has its roots in both the Handbook of Australian Soils and the Factual Key. The scheme’s use of mutually exclusive characteristics has led to Soil Orders containing a diverse range of soils, such as the Dermosols. The extent of these groupings has resulted in classes of soils sharing greater relationships with soils from other classes than they do with soils in the same class. Situations such as this arise from artificial classifications and highlight the need for natural classifications. Natural classifications accurately represent what is occurring in nature and are desirable because they represent evidence of a common history, process or mechanism. This study uses cladistics, a robust biological method that uncovers natural classifications, to assess the naturalness of the ASC. The analysis has the secondary aims of identifying natural soil orders and establishing which characters and tiers require revision. Two measures commonly used in cladistics, consistency index (CI) and retention index (RI), are used along with confidence levels generated by bootstrapping. The cladistic analysis undertaken consisted of coding 113 morphological and non-morphological characters used to identify 13 of the 14 Soil Orders in ASC into binary and multi-state matrices and analysis using a parsimony cladistic algorithm. The results suggest that, because of its low CI (0.196), the ASC is not a natural classification. However, certain Soil Orders of Organosols, Podosls and Vertosols, which all registered high CI, are natural. The analysis also indicated which soil morphological characters and Soil Orders require revision in order to make the ASC more natural, namely, soil colour and characters located in the Great Groups as well as Soil Orders such as Chromosols, Ferrosols and Dermosols. We conclude that cladistics offers a new avenue in discerning relationships between soils and in assessing the accuracy of, and identifying where improvements can be made in, the classifications used to identify them.

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Relationships between field texture and particle-size distribution in Australia and their implications

Soil Research ◽

10.1071/sr07051 ◽

2007 ◽

Vol 45 (6) ◽

pp. 428 ◽

Cited By ~ 6

Author(s):

Budiman Minasny ◽

Alex B. McBratney ◽

Damien J. Field ◽

Grant Tranter ◽

Neil J. McKenzie ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Classification System ◽

Soil Classification ◽

Particle Size Analysis ◽

Pedotransfer Functions ◽

Size Analysis ◽

Texture Contrast ◽

Australian Soil

This paper aims to establish the means and ranges of clay, silt, and sand contents from field texture classes, and to investigate the differences in the field texture classes and texture determined from particle-size analysis. The results of this paper have 2 practical applications: (1) to estimate the particle size distribution and its uncertainty from field texture as input to pedotransfer functions, and (2) to examine the criteria of texture contrast soils in the Australian Soil Classification system. Estimates of clay, silt, and sand content for each field texture class are given and this allows the field texture classes to be plotted in the texture triangle. There are considerable differences between field texture classes and particle-size classes. Based on the uncertainties in determining the clay content from field texture, we establish the probability of the occurrence of a texture contrast soil according to the Australian Soil Classification system, given the texture of the B2 horizon and its overlying A horizon. I enjoy doing the soil-texture feel test with my fingers or kneading a clay soil, which is a short step from ceramics or sculpture. Hans Jenny (1984)

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Australian Soil Classification

10.1071/9780643069817 ◽

2002 ◽

Cited By ~ 371

Author(s):

Raymond Isbell

Keyword(s):

Environmental Studies ◽

Soil Classification ◽

Soil Science ◽

Land Resource ◽

Research Programs ◽

Australian Soil ◽

Nation System

The Australian Soil Classification provides a framework for organising knowledge about Australian soils. It provides a means of communication among scientists and land managers. It is useful for those involved in environmental studies and for teachers of soil science. Since its publication in 1996, the Australian Soil Classification has been widely adopted and formally endorsed as the official nation system. It has proven to be of particular value in land resource survey and research programs. This revised edition includes some significant changes to the Tenosol soil order and these will substantially improve the utility of the system in southern and western parts of the continent.

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Australian Soil Classification: an Review

Korean Journal of Soil Science and Fertilizer ◽

10.7745/kjssf.2016.49.1.093 ◽

2016 ◽

Vol 49 (1) ◽

pp. 93-114 ◽

Cited By ~ 1

Author(s):

Byung-Keun Hyun ◽

Yeon-Kyu Sonn ◽

Hyun-Jun Cho ◽

Kangho Jung ◽

Jung-won Choi ◽

...

Keyword(s):

Soil Classification ◽

Australian Soil

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Australian Soil Classification

10.1071/9781486304646 ◽

2016 ◽

Cited By ~ 54

Author(s):

R Isbell ◽

Keyword(s):

Working Group ◽

Soil Classification ◽

National Committee ◽

Land Resource ◽

Acid Sulfate Soils ◽

Basic Requirement ◽

National System ◽

New Knowledge ◽

Sulfate Soils ◽

Australian Soil

The Australian Soil Classification provides a framework for organising knowledge about Australian soils by allocating soils to classes via a key. Since its publication in 1996, this book has been widely adopted and formally endorsed as the official national system. It has provided a means of communication among scientists and land managers and has proven to be of particular value in land resource survey and research programs, environmental studies and education. Classification is a basic requirement of all science and needs to be periodically revised as knowledge increases. This Second Edition of The Australian Soil Classification includes updates from a working group of the National Committee on Soil and Terrain (NCST), especially in regards to new knowledge about acid sulfate soils (sulfidic materials). Modifications include expanding the classification to incorporate different kinds of sulfidic materials, the introduction of subaqueous soils as well as new Vertosol subgroups, new Hydrosol family criteria and the consistent use of the term reticulate. All soil orders except for Ferrosols and Sodosols are affected by the changes.

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Comparisons between USDA soil taxonomy and the Australian Soil Classification system II: Comparison of order, suborder and great group taxa

Geoderma ◽

10.1016/j.geoderma.2018.02.022 ◽

2018 ◽

Vol 322 ◽

pp. 48-55 ◽

Cited By ~ 6

Author(s):

Philip Hughes ◽

Alex B. McBratney ◽

Budiman Minasny ◽

Jingyi Huang ◽

Erika Micheli ◽

...

Keyword(s):

Classification System ◽

Soil Classification ◽

Soil Taxonomy ◽

Australian Soil

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Classification issues for the Hydrosol and Organosol Soil Orders to better encompass surface acidity and deep sulfidic horizons in acid sulfate soils

Soil Research ◽

10.1071/sr04136 ◽

2005 ◽

Vol 43 (5) ◽

pp. 629 ◽

Cited By ~ 1

Author(s):

B. P. Wilson

Keyword(s):

Surface Acidity ◽

Laboratory Data ◽

Soil Classification ◽

Soil Survey ◽

Acid Sulfate Soils ◽

Risk Map ◽

Acid Sulfate ◽

Near Surface ◽

Sulfate Soils ◽

Australian Soil

The Australian Soil Classification (ASC) suggests that, owing to a lack of data available at the time of publication, modifications may be required for those soils containing sulfidic or sulfuric materials. The soil survey since undertaken for the acid sulfate soil risk maps of coastal NSW has provided sufficient data to suggest changes to the ASC, specifically with reference to horizons overlying sulfidic and sulfuric materials, and deep sulfidic materials. During the risk map survey a database of 308 sulfidic or sulfuric profiles was produced that contains descriptions, classifications, and laboratory data. It is this database that is examined in this paper. While the ASC successfully encompasses most characteristics which are important for land use, many of the risk map profiles contained an acidic, non acid sulfate, near surface layer that is not encompassed by the ASC. Hence, it is suggested here that a Supra acidic subgroup be included in the Hydrosol and Organosol Soil Orders to signify a near surface horizon with a pH <5.5 which is not sulfuric and which does not qualify as a Melacic horizon. The inclusion of an additional class to encompass deep sulfidic materials is also suggested for Hydrosols but, due to lack of data, not for other soil orders.

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Mean Residence Time of Soil Organic Carbon in Aggregates Under Contrasting Land Uses Based on Radiocarbon Measurements

Radiocarbon ◽

10.2458/azu_js_rc.v55i1.16179 ◽

2013 ◽

Vol 55 (1) ◽

pp. 127-139 ◽

Cited By ~ 7

Author(s):

Sheikh M Fazle Rabbi ◽

Quan Hua ◽

Heiko Daniel ◽

Peter V Lockwood ◽

Brian R Wilson ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Residence Time ◽

Mean Residence Time ◽

Soil Aggregates ◽

Soil Classification ◽

Land Uses ◽

Stable Pool ◽

The Mean ◽

Australian Soil

Radiocarbon is a useful tool for studying carbon dynamics in soil aggregates. The objective of the current study was to determine the mean residence time (MRT) of soil organic carbon (SOC) in macroaggregates and microaggregates under contrasting land uses. Contrasting land uses investigated at Alfisol (equivalent to Dermosol in Australian Soil Classification) sites were native pasture (NP), crop-pasture rotation (CP), and Eucalypt woodland (WL), whereas in Oxisol (Ferrosol in Australian Soil Classification) sites, land uses comprised improved pasture (IP), cropping (CR), and forest (FR). Soil aggregates were separated into macroaggregates (250–2000 μm) and microaggregates (53–250 μm) by wet-sieving, and their14C signatures were determined by accelerator mass spectrometry (AMS). The14C activity in both macro- and microaggregates was >100 pMC, indicating the presence of post-bomb carbon in the soil. The mean residence time (MRT) of SOC in macro- and microaggregates (MRTagg) was on average 68 yr longer in the Oxisol compared with that in the Alfisol. The MRTaggin microaggregates was 10 yr longer than that of macroaggregates in the Alfisol. However, the MRTaggin microaggregates was 50 yr shorter compared to macroaggregates in the Oxisol.The MRT of macro- and microaggregates can be separated into active, slow, and stable SOC pools. Among the 3 SOC pools, the MRT of the stable pool is of higher significance in terms of SOC stabilization in soil aggregates because of its longer MRT. However, isolation and direct MRT estimation of the stable SOC pool is difficult. The MRT of active and slow SOC pools associated with macro- and microaggregates was measured using a SOC mineralization experiment to estimate the MRT of the stable SOC pool under contrasting land uses by applying a mass balance criterion. The MRT of active (MRTA) and slow (MRTS) SOC pools in macro- and microaggregates varied between 1–50 days and 13–38 yr, respectively. The estimated MRT of the stable pool carbon (MRTP) in microaggregates was 897 yr longer compared to that of macroaggregates in the Alfisol. However, in the Oxisol, MRTPin microaggregates was 568 yr shorter than that of macroaggregates. Among the land uses, WL in Alfisol and CR in Oxisol had longer MRTaggand MRTPcompared to other land uses.

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Australian Soil Classification

10.1071/9781486314782 ◽

2021 ◽

Author(s):

R Isbell ◽

Keyword(s):

Working Group ◽

Soil Classification ◽

National Committee ◽

New Order ◽

Land Resource ◽

Basic Requirement ◽

New Knowledge ◽

Land Survey ◽

Australian Soil ◽

Main Change

The Australian Soil Classification provides a framework for organising knowledge about Australian soils by allocating soils to classes via a key. Since its publication in 1996, this book has been widely adopted and formally endorsed as the official national system. It has provided a means of communication among scientists and land managers and has proven to be of particular value in land resource survey and research programs, environmental studies and education. Classification is a basic requirement of all science and needs to be periodically revised as knowledge increases. This third edition of The Australian Soil Classification includes updates from a working group of the National Committee on Soil and Terrain (NCST). The main change in this edition accommodates new knowledge and understanding of the significance, nature, distribution and refined testing for soils comprising deep sands, leading to the inclusion of a new Order, the Arenosols. The introduction of the Arenosols Order led to a review and changes to Calcarosols, Tenosols and Rudosols. The Australian Soil Classification is Volume 4 in the Australian Soil and Land Survey Handbooks Series.

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