Soil pH — Benchmark Detail

Benchmark Value

No specific value — see range

Range: 6 to 8 pH

Optimal Range: 6 to 8

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 13 benchmarks together — the OptimalRange form drives the primary score, while 12 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

A benchmark range of pH(w) 6.0 – 8.0 is proposed as the reference for best available condition.

Metric Definition:

Soil pH measured in water (pHw)

Benchmark Definition:

This benchmark represents the natural pH range of healthy, intact native woodland soils in the Arid Mountain Ranges & Uplands biome under production forestry, indicating a safe operating space for resilient ecosystem function.

Justification:

Derived from the natural pH range of healthy native woodland ecosystems (e.g., Peppermint Box grassy woodlands) within the Flinders Lofty Block bioregion, serving as a proxy due to absence of production forestry.

Sources (1)

Preview of Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed August 9, 2025,

Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed August 9, 2025, Journal

Northern Mount Lofty Ranges and Southern Flinders Ranges soil descriptions

View Source

Supporting Sources (6)

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,

Direct Evidence 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

Government of South Australia, Department for Environment and Water. (n.d.). Soil Health and Condition.

Direct Evidence Government

Soil acidity - Department for Environment and Water

View Source

Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed July 30, 2025,

Contextual Support GreyLiterature

Peppermint Box (Eucalyptus odorata) Grassy Woodland of South Australia, accessed July 30, 2025,

View Source

Private Forestry Guidance Materials, accessed August 1, 2025,

Direct Evidence Journal

Research and advice from the Grains Research and Development Corporation (GRDC) for the South Australian Mallee region

View Source

Soil acidity is starting to emerge in the Southern Mallee on certain soils types. - GRDC, accessed July 30, 2025,

Direct Evidence

Soil acidity is starting to emerge in the Southern Mallee on certain soils types. - GRDC, accessed July 30, 2025,

View Source

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

Direct Evidence Government

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

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Production Forestry
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

This range reflects the natural variability of soils from slightly acidic to moderately alkaline and represents a safe operating space for resilient ecosystem function. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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