Soil pH

AUS-AIF-LVG-SPH General Moderate confidence

Benchmark Value

7.7 pH
Thresholds: Lower: —, Upper: 7.7
Direction: Higher is desirable ↑
Form: UpperThreshold

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 OptimalRange Guard MinimumOnly Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard UpperThreshold Guard MinimumOnly Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard LowerThreshold Guard UpperThreshold Guard OptimalRange Guard

Evidence & Context

A detrimental upper threshold is identified at a pH (measured in water) greater than 8.5 (approximately pHCaCl2​​ > 7.7).

Metric Definition:

Detrimental upper threshold for soil pH measured in pHCaCl2​​

Benchmark Definition:

This benchmark defines the detrimental upper soil pH threshold above which ecosystem health is impaired due to sodicity in the Arid Inland Floodplains & Ephemeral River Systems biome under livestock grazing and pasture.

Justification:

pH levels above this threshold are strongly correlated with sodicity, which causes clay dispersion, catastrophic loss of soil structure, and induced micronutrient deficiencies.

Sources (1)

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 Government

Repairing gully erosion in Western Australia | Department of Primary ...

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

Soil pH | Environment, land and water - Queensland Government, accessed August 28, 2025,

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

Soil acidity | Soil | Farm management - Agriculture Victoria, accessed August 28, 2025

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

Arnhem Plateau Sandstone Shrubland Complex Ecological Community - listing advice, accessed May 20, 2025

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

Soil Characteristics and Management Options | VRO - Victorian Resources Online

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

Australian Soil: Definition, Classification, Types and Quality - Access EP

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

Australian Soil Classification edition 3 - CALCAROSOLS

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

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

The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed August 28, 2025,

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 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) Riverine vegetation of inland south-eastern Australia - ResearchGate

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 Acidity - Ag Excellence Alliance, accessed July 10, 2025,
Soil Acidity - Ag Excellence Alliance, accessed July 10, 2025,
Contextual Support GreyLiterature

Soil pH and Microbial Life - Number Analytics, accessed July 7, 2025,

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

Soil and Landscape Grid of Australia - esoil.io, accessed July 26, 2025,

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

The relationships between land management practices and soil condition and the quality of ecosystem services delivered from agri - DAFF, accessed July 28, 2025,

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

Soil pH - SA | Fact Sheets | soilquality.org.au, accessed July 30, 2025,

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

Improving Soil Structure and pH Levels (DPIFM_NT) - Department of ..., accessed July 20, 2025

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

View Source
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

The pH of Australian soils: field results from a national survey - CSIRO Publishing, accessed August 28, 2025,

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

Understanding soil pH

View Source
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

View Source
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

Potassium for high-performing pastures | Nutrient Advantage, accessed July 28, 2025,

View Source

Context

  • Region Australia
  • Biome Arid Inland Floodplains & Ephemeral River Systems
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 24 Mar 2026

Notes

This is a primary degradation pathway for these soils. The source states pH measured in water is >8.5, approximately pHCaCl2 >7.7; this approximation is clearly justified.

Related Benchmarks

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

— pH High
Livestock Grazing & Pasture · Pristine Reference
OptimalRange Active v1
5 pH Moderate
Livestock Grazing & Pasture · Pristine Reference
LowerThreshold Active v1