Soil pH — Benchmark Detail

Benchmark Value

5.5 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

The reference value is to maintain the topsoil (0-10 cm) pH(CaCl₂) at or above 5.5.

Metric Definition:

Topsoil (0-10 cm) pH measured in 0.01 M CaCl₂ solution

Benchmark Definition:

This benchmark sets a proactive management target to maintain soil pH at or above 5.5 in temperate grazing systems to prevent subsoil acidification and support ecosystem health.

Justification:

Maintaining a pH(CaCl₂) of ≥5.5 eliminates aluminium toxicity, optimises nutrient availability, and enables slow amelioration of subsoil acidity.

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.

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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

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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,

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Context

Region Australia
Biome Temperate Grassy Woodlands & Plains
Land Use Livestock Grazing & Pasture
Assessment Not Stated
Evidence Type HealthyOperationalRange

Lifecycle

Status Active
Version 1
Effective From 9 Jun 2026

Notes

This benchmark represents a proactive management target for achieving high ecological health and long-term resilience in temperate grazing systems. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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