Soil pH

AUS-AIF-LVG-SPH General Moderate confidence

Benchmark Value

5 pH
Direction: Higher is desirable ↑
Form: MinimumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context. The scoring engine uses 19 benchmarks together — the OptimalRange form drives the primary score, while 18 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard OptimalRange Guard Point Guard OptimalRange Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard MaximumOnly Guard

Evidence & Context

A lower critical threshold for ecosystem health is identified at pHCaCl2​​ 5.0. Below this level, acidification leads to nutrient deficiencies and reduced microbial activity.

Metric Definition:

Critical lower threshold for soil pH indicating onset of acidification stress and ecosystem health impairment.

Benchmark Definition:

This benchmark marks the critical lower pH limit below which soil acidification harms ecosystem health in Australian arid inland floodplains under livestock grazing.

Justification:

Below pHCaCl2​​ 5.0, acidification leads to nutrient deficiencies and reduced microbial activity.

Sources (1)

Preview of Soil Acidity - Ag Excellence Alliance, accessed July 10, 2025,
Soil Acidity - Ag Excellence Alliance, accessed July 10, 2025, GreyLiterature

Soil Health - Dairy Australia

View Source

Supporting Sources (32)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,
(PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,
Direct Evidence Journal

Caritat, P. de, & Cooper, M. (2011). The pH of Australian soils: Field results from a national survey. Soil Research, 49, 172-182.

View Source
Preview of Agriculture Victoria. (2024). Soil acidity.
Agriculture Victoria. (2024). Soil acidity.
Contextual Support Government

Agriculture Victoria. (2025). Soil acidity. Farm Management.

View Source
Preview of ASC - VERTOSOLS - Soil Science Australia
ASC - VERTOSOLS - Soil Science Australia
Contextual Support

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase

View Source
Preview of AusEarthed. (n.d.). Soil Reading.
AusEarthed. (n.d.). Soil Reading.
Contextual Support Journal

Victorian Resources Online | Resources | Support and resources ..., accessed July 21, 2025,

View Source
Preview of Australian Soil Classification edition 3 - CALCAROSOLS
Australian Soil Classification edition 3 - CALCAROSOLS
Contextual Support Government

Monitoring changes in soil salinity and sodicity to depth, at a ...

View Source
Preview of Australian Soil: Definition, Classification, Types and Quality - Access EP, accessed July 30, 2025
Australian Soil: Definition, Classification, Types and Quality - Access EP, accessed July 30, 2025
Contextual Support GreyLiterature

Appendix H - Water Infiltration Modelling - NT EPA, accessed July 16, 2025,

View Source
Preview of Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025
Common soil types | Environment, land and water - Queensland Government, accessed August 9, 2025
Contextual Support Government

Sodic & Alkaline Soil - Soil Quality Knowledge Base

View Source
Preview of Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed August 5, 2025,
Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed August 5, 2025,
Contextual Support Journal

Ludwig, J.A., Bastin, G.N., Chewings, V.H., Eager, R.W., and Liedloff, A.C. (2005). Clearing savannas for use as rangelands in Queensland: Altered landscapes and water-erosion processes. Rangeland Journal, 27(2), 135-149.

View Source
Preview of Liming acidic soils creates profits, land use options but often more emissions - CSIRO Publishing
Liming acidic soils creates profits, land use options but often more emissions - CSIRO Publishing
Contextual Support Journal

Liming acidic soils creates profits, land use options but often more emissions - CSIRO Publishing

View Source
Preview of Living soils in agriculture | TERN Australia, accessed July 25, 2025,
Living soils in agriculture | TERN Australia, accessed July 25, 2025,
Contextual Support Government

Living soils in agriculture | TERN Australia, accessed July 16, 2025,

View Source
Preview of Manage soil acidity | EverGraze More livestock from perennials
Manage soil acidity | EverGraze More livestock from perennials
Contextual Support GreyLiterature

Manage soil acidity | EverGraze More livestock from perennials, accessed July 18, 2025,

View Source
Preview of Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers, accessed July 30, 2025,
Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers, accessed July 30, 2025,
Contextual Support Journal

Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed July 10, 2025,

View Source
Preview of Managing soils - Department of Primary Industries and Regional Development, accessed August 12, 2025
Managing soils - Department of Primary Industries and Regional Development, accessed August 12, 2025
Direct Evidence Government

Repairing gully erosion in Western Australia | Department of Primary ..., accessed July 17, 2025

View Source
Preview of National Guidance on Acid Sulfate Soils - Water Quality Australia
National Guidance on Acid Sulfate Soils - Water Quality Australia
Contextual Support GreyLiterature

Manage soil acidity – South Coast Sandplain WA | EverGraze More livestock from perennials

View Source
Preview of Pasture management for South East Queensland - FutureBeef, accessed July 19, 2025
Pasture management for South East Queensland - FutureBeef, accessed July 19, 2025
Contextual Support Journal

Understanding Soils and Nutrients - Australian Native Plants Society (Australia)

View Source
Preview of Pastures and acid soils - NSW Government
Pastures and acid soils - NSW Government
Contextual Support Journal

pH in Soil and Nutrient Availability - Australian Scientific Pty Ltd - Water Quality Division, accessed August 28, 2025

View Source
Preview of Regenerative Grazing: 3 Different Approaches - Shorthandstories.com, accessed August 5, 2025,
Regenerative Grazing: 3 Different Approaches - Shorthandstories.com, accessed August 5, 2025,
Contextual Support GreyLiterature

Regenerative Grazing: 3 Different Approaches - Shorthandstories.com

View Source
Preview of Riverine ecosystems and health: Soil-landscapes - Australian ...
Riverine ecosystems and health: Soil-landscapes - Australian ...
Contextual Support Journal

A consistent vegetation classification for wetland conservation and management in the Murray–Darling Basin, Australia - CSIRO Publishing

View Source
Preview of Rivers, wetlands and floodplains | Murray–Darling Basin Authority
Rivers, wetlands and floodplains | Murray–Darling Basin Authority
Contextual Support GreyLiterature

(PDF) Regenerative capacity of old‐fields on semi‐arid floodplains ..., accessed July 16, 2025

View Source
Preview of Soil acidification | Meat & Livestock Australia - MLA
Soil acidification | Meat & Livestock Australia - MLA
Contextual Support Journal

Soil acidification | Meat & Livestock Australia - MLA

View Source
Preview of Soil and Landscape Grid of Australia - esoil.io, accessed July 13, 2025
Soil and Landscape Grid of Australia - esoil.io, accessed July 13, 2025
Contextual Support Government

UPTAKE OF ARSENIC BY NATIVE PLANTS GROWING ON GOLD TAILINGS IN WESTERN AUSTRALIAN RANGELANDS1

View Source
Preview of Soil condition | NSW State of the Environment
Soil condition | NSW State of the Environment
Contextual Support Government

Soils of South Australia - Department for Environment and Water

View Source
Preview of Soil condition | NSW State of the Environment, accessed August 10, 2025,
Soil condition | NSW State of the Environment, accessed August 10, 2025,
Contextual Support Government

Analysing water sensitive urban design options - Australian Water Association

View Source
Preview of Soil pH - SA | Fact Sheets | soilquality.org.au
Soil pH - SA | Fact Sheets | soilquality.org.au
Contextual Support Government

Soil Acidity - NSW | Fact Sheets | soilquality.org.au

View Source
Preview of Soil pH | Environment, land and water - Queensland Government, accessed July 30, 2025,
Soil pH | Environment, land and water - Queensland Government, accessed July 30, 2025,
Contextual Support Government

Australian dryland soils are acidic and nutrient‐depleted, and have unique microbial communities compared with other drylands - Arid Ecology Lab

View Source
Preview of Soil Reading - Australian Earth Science Education
Soil Reading - Australian Earth Science Education
Contextual Support Government

Soil Reading - Australian Earth Science Education

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Preview of The grazier's guide to pastures - NSW Department of Primary Industries
The grazier's guide to pastures - NSW Department of Primary Industries
Contextual Support Journal

The grazier's guide to pastures - NSW Department of Primary Industries

View Source
Preview of The pH of Australian soils: field results from a national survey - CSIRO Publishing, accessed July 25, 2025,
The pH of Australian soils: field results from a national survey - CSIRO Publishing, accessed July 25, 2025,
Direct Evidence Journal

Soil pH Explained - Soil Quality Knowledge Base

View Source
Preview of Understanding soil pH
Understanding soil pH
Contextual Support Government

Understanding soil pH

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Preview of Update and expansion of the soil and landscape grid of Australia - ResearchGate
Update and expansion of the soil and landscape grid of Australia - ResearchGate
Methodology Source Journal

Update and expansion of the soil and landscape grid of Australia - ResearchGate

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Preview of Victorian Resources Online | Resources | Support and resources ...
Victorian Resources Online | Resources | Support and resources ...
Contextual Support

Victorian Resources Online | Resources | Support and resources ...

View Source
Preview of www.barrierreef.org, accessed on May 25, 2025,
www.barrierreef.org, accessed on May 25, 2025,
Contextual Support Journal

Regenerative Agriculture Program restoring soil pH case study: Macdonald, Whites Flat/Koppio, accessed July 18, 2025,

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Livestock Grazing & Pasture
  • Assessment Not Stated
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 9 Jun 2026

Notes

Severe aluminium toxicity impacts most pasture species below pHCaCl2​​ 4.8. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-AIF-LVG-SPH family.

— pH Moderate
Livestock Grazing & Pasture · Not Stated
OptimalRange Active v1
7.7 pH Moderate
Livestock Grazing & Pasture · Not Stated
MaximumOnly Active v1