Soil pH

AUS-ASC-AGR-SPH General Moderate confidence

Benchmark Value

No specific value — see range
Range: 5 to 5.5 pH
Thresholds: Lower: 4.5, Upper: 6
Optimal Range: 5 to 5.5
Direction: Higher is desirable ↑
Form: OptimalRange

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 8 benchmarks together — the OptimalRange form drives the primary score, while 7 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

Consequently, a derived optimal topsoil range of pHCaCl2​​ 5.0 - 5.5 (approximately pHwater​ 5.5 - 6.3) is proposed.

Metric Definition:

Soil pH measured in calcium chloride (pH(CaCl₂)) in topsoil for sustainable agricultural crop production in Australian Alpine and Subalpine Complex.

Benchmark Definition:

This benchmark defines an optimal soil pH range in calcium chloride solution for sustainable agricultural crop production in Australia's Alpine and Subalpine Complex. It balances the needs of acid-tolerant crops with the ecological integrity of naturally acidic soils.

Justification:

Derived due to absence of specific documented benchmarks; based on synthesis of natural soil pH ranges, agronomic principles, and regenerative agriculture goals.

Sources (3)

Preview of Agriculture Victoria. (2024). Soil acidity.
Agriculture Victoria. (2024). Soil acidity. Government

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

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Preview of Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - ResearchGate, accessed on May 31, 2025
Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - ResearchGate, accessed on May 31, 2025 Journal

Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - ResearchGate

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Preview of NSW Department of Primary Industries. (2021). Soil Acidity and Liming (AC.19).
NSW Department of Primary Industries. (2021). Soil Acidity and Liming (AC.19). Government

Understanding soil pH

View Source

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Nitrogen dynamics in alpine soils of south-eastern Australia, accessed on May 31, 2025
(PDF) Nitrogen dynamics in alpine soils of south-eastern Australia, accessed on May 31, 2025
Contextual Support GreyLiterature

Australia state of the environment 2021: land, accessed on May 28, 2025

View Source
Preview of 4. SOIL PH AND LIME | Nutrient Management, accessed on May 31, 2025
4. SOIL PH AND LIME | Nutrient Management, accessed on May 31, 2025
Contextual Support GreyLiterature

4. SOIL PH AND LIME | Nutrient Management, accessed on May 31, 2025

View Source
Preview of Australian Alps - DCCEEW, accessed August 3, 2025,
Australian Alps - DCCEEW, accessed August 3, 2025,
Contextual Support Government

Alpine sphagnum bogs and associated fens - EPBC Act policy statement 3.16

View Source
Preview of Australian Alps - DCCEEW, accessed on May 31, 2025
Australian Alps - DCCEEW, accessed on May 31, 2025
Contextual Support Government

Review of water quality studies in the Australian Alps

View Source
Preview of Australian Soils and Landscapes | CSIRO Publishing, accessed on May 31, 2025
Australian Soils and Landscapes | CSIRO Publishing, accessed on May 31, 2025
Contextual Support GreyLiterature

Australian Soils and Landscapes | CSIRO Publishing

View Source
Preview of Effects of soil pH on the growth, soil nutrient composition, and rhizosphere microbiome of Ageratina adenophora - PMC - PubMed Central, accessed July 30, 2025,
Effects of soil pH on the growth, soil nutrient composition, and rhizosphere microbiome of Ageratina adenophora - PMC - PubMed Central, accessed July 30, 2025,
Contextual Support Journal

Do regenerative grazing management practices improve vegetation ...

View Source
Preview of Experimental warming and fire alter fluxes of soil nutrients in sub ..., accessed on May 31, 2025
Experimental warming and fire alter fluxes of soil nutrients in sub ..., accessed on May 31, 2025
Contextual Support

Experimental warming and fire alter fluxes of soil nutrients in sub-alpine open heathland - Inter-Research, accessed May 10, 2026

View Source
Preview of Focus Group – Regenerative agriculture for soil health - EU CAP Network
Focus Group – Regenerative agriculture for soil health - EU CAP Network
Contextual Support Journal

grazing - in THE AUSTRALIAN ALPS

View Source
Preview of Full article: Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - Taylor & Francis Online, accessed May 28, 2025
Full article: Impacts of Road Disturbance on Soil Properties and on Exotic Plant Occurrence in Subalpine Areas of the Australian Alps - Taylor & Francis Online, accessed May 28, 2025
Contextual Support Journal

www.nrc.nsw.gov.au, accessed on May 27, 2025

View Source
Preview of Full article: Long-term alpine summit vegetation cover change: Divergent trajectories driven by climate warming and fire, accessed on May 25, 2025,
Full article: Long-term alpine summit vegetation cover change: Divergent trajectories driven by climate warming and fire, accessed on May 25, 2025,
Contextual Support

Assessing alpine vegetation dynamics using long-term ecological monitoring amidst rapid climate change

View Source
Preview of grazing - in THE AUSTRALIAN ALPS, accessed August 3, 2025,
grazing - in THE AUSTRALIAN ALPS, accessed August 3, 2025,
Contextual Support Journal

What is your soil pH and what is ideal? - Baileys Fertilisers

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 – South West Victoria (Lower), accessed on May 31, 2025
Manage soil acidity – South West Victoria (Lower), accessed on May 31, 2025
Contextual Support GreyLiterature

4. SOIL PH AND LIME | Nutrient Management

View Source
Preview of oleander-blackbird-fhxj.squarespace.com, accessed on May 31, 2025
oleander-blackbird-fhxj.squarespace.com, accessed on May 31, 2025
Contextual Support Journal

oleander-blackbird-fhxj.squarespace.com

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Preview of openresearch-repository.anu.edu.au, accessed on May 31, 2025
openresearch-repository.anu.edu.au, accessed on May 31, 2025
Contextual Support Journal

openresearch-repository.anu.edu.au, accessed on May 31, 2025,

View Source
Preview of openresearch-repository.anu.edu.au, accessed on May 31, 2025
openresearch-repository.anu.edu.au, accessed on May 31, 2025
Contextual Support

openresearch-repository.anu.edu.au, accessed on May 31, 2025

Preview of Regenerative Organic Agriculture and Human Health: The Interconnection Between Soil, Food Quality, and Nutrition - MDPI, accessed on May 31, 2025
Regenerative Organic Agriculture and Human Health: The Interconnection Between Soil, Food Quality, and Nutrition - MDPI, accessed on May 31, 2025
Contextual Support Journal

Water Quality Australia

View Source
Preview of Soil Acidity - NSW | Fact Sheets | soilquality.org.au, accessed on May 31, 2025
Soil Acidity - NSW | Fact Sheets | soilquality.org.au, accessed on May 31, 2025
Contextual Support Government

Managing soils - Department of Primary Industries and Regional Development

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

Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central

View Source
Preview of What is your soil pH and what is ideal? - Baileys Fertilisers, accessed on May 31, 2025
What is your soil pH and what is ideal? - Baileys Fertilisers, accessed on May 31, 2025
Contextual Support GreyLiterature

What is your soil pH and what is ideal? - Baileys Fertilisers, accessed on May 31, 2025

View Source
Preview of www.environment.nsw.gov.au, accessed on May 25, 2025,
www.environment.nsw.gov.au, accessed on May 25, 2025,
Contextual Support

The Australian Alps Bioregion - Environment and Heritage, accessed on May 27, 2025,

View Source

Context

  • Region Australia
  • Biome Alpine and Subalpine Complex
  • Land Use Agricultural Crop Production
  • Assessment Not Stated
  • Evidence Type TargetCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 2 Jun 2026

Notes

The range balances acid-tolerant crop needs with ecological integrity of naturally acidic alpine soils. Lower threshold at pH 4.5 marks critical toxicity and nutrient deficiency risk; upper threshold at pH 6.0 marks potential ecological and agronomic detriment. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.