Soil pH — Benchmark Detail

Benchmark Value

4.8 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.

Evidence & Context

Severe degradation occurring below pH 4.8.

Metric Definition:

Soil pH measured in 0.01 M CaCl₂ solution indicating severe degradation threshold

Benchmark Definition:

This benchmark defines the soil pH threshold below which severe ecological degradation occurs in temperate grazing systems.

Justification:

pH below 4.8 leads to aluminium and manganese toxicity, severely inhibiting soil biological activity.

Sources (1)

Preview of Procedure for Soil Respiration (CO2 Evolution from Rewetting a Dried Soil) - Soil Fertility, accessed July 9, 2025

Procedure for Soil Respiration (CO2 Evolution from Rewetting a Dried Soil) - Soil Fertility, accessed July 9, 2025 GreyLiterature

Tool 6.7 Soil health benchmarks and guidelines for managing ...

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Supporting Sources (13)

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

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

View Source

Agriculture Victoria. (2024). Soil acidity.

Contextual Support Government

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

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

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

How should we manage our soils to increase soil carbon?, accessed May 10, 2026

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Do grazing intensity and herbivore type affect soil health? Insights from a semi-arid productivity gradient, accessed July 24, 2025

Contextual Support Journal

Soil acidification | .Meat & Livestock Australia

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Managing soils - Department of Primary Industries and Regional Development, accessed August 12, 2025

Contextual Support Government

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

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Preview of Natural Temperate Grassland of the South Eastern Highlands: a nationally protected ecological community - DCCEEW, accessed August 12, 2025,

Natural Temperate Grassland of the South Eastern Highlands: a nationally protected ecological community - DCCEEW, accessed August 12, 2025,

Contextual Support Journal

Natural Temperate Grassland of the South Eastern ... - DCCEEW

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

Contextual Support Government

Understanding soil pH

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Pastures and acid soils - NSW Government

Contextual Support Journal

What do you see and when? What could this indicate? What test can I do to confirm? - MLA

View Source

Soil pH - SA | Fact Sheets | soilquality.org.au

Contextual Support Government

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

View Source

SoilQuality.org.au. (n.d.). Soil Acidity Factsheet.

Contextual Support

Soil Acidity | Fact Sheets | soilquality.org.au, accessed July 20, 2025,

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Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025

Contextual Support Government

Agriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.

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What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,

Contextual Support Government

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed July 18, 2025

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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 Temperate Grassy Woodlands & Plains
Land Use Livestock Grazing & Pasture
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 9 Jun 2026

Notes

Represents a state of severe ecological dysfunction with dominance of acid-tolerant weeds. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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