Soil pH — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 8.3 to 8.6 pH

Optimal Range: 8.3 to 8.6

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.

Evidence & Context

Benchmark for Calcareous Soils: The observed range of pH(water) 8.3 to 8.6 converts to an approximate pHCaCl2 range of 7.5 to 7.8.

Metric Definition:

Topsoil pH measured in water (pH(water)) for calcareous soils representing the inherent alkaline state in Australian Arid Mountain Ranges & Uplands.

Benchmark Definition:

Reference benchmark range for soil pH in calcareous soils under sustainable cropping in Australian Arid Mountain Ranges & Uplands.

Justification:

This range represents the naturally alkaline end of the spectrum where the presence of free lime buffers the pH at a high level. The goal is to prevent further alkalinization due to management practices.

Sources (1)

Eyre Peninsula Farming Systems Summary 2021 Journal

Eyre Peninsula Farming Systems Summary 2021

View Source

Supporting Sources (19)

Additional references from the underlying research that informed this benchmark.

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

Contextual Support Journal

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

View Source

Preview of Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 2, 2025,

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 2, 2025,

Contextual Support Government

Northern and Yorke | Soil management - Landscape South Australia, accessed July 28, 2025

View Source

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 5, 2025,

Contextual Support Journal

Root Structure and Functioning for Efficient Acquisition of Phosphorus: Matching Morphological and Physiological Traits

View Source

Balancing pasture development options for landscape diversity - CiteSeerX, accessed July 28, 2025

Contextual Support GreyLiterature

Balancing pasture development options for landscape diversity - CiteSeerX, accessed July 28, 2025

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Discover the Top 6 Benefits of Regenerative Farming in Australia, accessed July 16, 2025

Contextual Support Journal

Soil Health: Supporting Rural Industries in the Wet Tropics, accessed August 28, 2025,

View Source

Farming more sustainably by managing soil acidity, accessed July 28, 2025,

Contextual Support Journal

Soil pH Explained - Soil Quality Knowledge Base, accessed July 28, 2025

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Investigating the impacts of groundwater on soil properties and ..., accessed July 28, 2025

Contextual Support Journal

Investigating the impacts of groundwater on soil properties and ..., accessed July 28, 2025

View Source

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 Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,

Contextual Support Journal

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 28, 2025,

View Source

Soil Constraints in an Arid Environment—Challenges, Prospects, and Implications - MDPI, accessed July 6, 2025,

Contextual Support Journal

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

View Source

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

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

Soil pH in northern and southern areas of the WA wheatbelt - DPIRD's Digital library, accessed July 28, 2025

Contextual Support Government

Soil pH in northern and southern areas of the WA wheatbelt - DPIRD's Digital library, accessed July 28, 2025

View Source

Soil Quality Knowledge Base. (n.d.). Soil pH.

Contextual Support GreyLiterature

Working with bio-amendments: Insights from cropping farmers - Soils For Life, accessed July 7, 2025,

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The extent of surface soil acidity in the relatively intensive... | Download Table - ResearchGate, accessed July 28, 2025

Contextual Support

Agricultural production system in arid and semi-arid regions, accessed August 28, 2025,

View Source

The pH of Australian soils: field results from a national survey - CSIRO Publishing, accessed July 25, 2025,

Contextual Support Journal

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

View Source

Tool 6.7 Soil health benchmarks and guidelines for managing problem soils, accessed July 28, 2025

Contextual Support Journal

LawrieCo2 Soil Carbon Regeneration System, accessed July 28, 2025

View Source

Preview of Transforming Agriculture in the Pilbara: Newman managed aquifer recharge (MAR) feasibility assessment - CSIRO Research Publications Repository, accessed July 28, 2025

Transforming Agriculture in the Pilbara: Newman managed aquifer recharge (MAR) feasibility assessment - CSIRO Research Publications Repository, accessed July 28, 2025

Contextual Support GreyLiterature

Transforming Agriculture in the Pilbara: Newman managed aquifer recharge (MAR) feasibility assessment - CSIRO Research Publications Repository, accessed July 28, 2025

View Source

Water repellent soils - CSIRO

Contextual Support Government

Water repellent soils - CSIRO, accessed July 28, 2025

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 24 Mar 2026

Notes

Lower Critical Threshold: 4.8 pH. Upper Detrimental Threshold: 8.2 pH. This pH is at the very upper limit of the optimal range and carries a risk of micronutrient deficiencies. Careful management is required to prevent further alkalinization.

Related Benchmarks

Other benchmarks in the AUS-AMR-AGR-SPH family.