Soil pH — Benchmark Detail

Benchmark Value

7.5 pH

Direction: Higher is desirable ↑

Form: Point

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 6 benchmarks together — the OptimalRange form drives the primary score, while 5 guard(s) constrain the result.

Contributing Benchmarks

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

Evidence & Context

The benchmark of pH 7.5 (1:5 water) represents the median condition in protected natural areas within this biome, reflecting the naturally neutral-to-alkaline soils shaped by a semi-arid climate and calcareous geology.

Metric Definition:

Soil pH measured in a 1:5 soil-to-water solution (pHw) in the topsoil layer (0-10 cm).

Benchmark Definition:

Median soil pH value in protected natural areas within the temperate semi-arid shrublands and open woodlands biome.

Justification:

Derived from a statistical analysis of millions of soil pH data points from the Soil and Landscape Grid of Australia, representing the best available condition in conservation areas.

Sources (1)

Soil and Landscape Grid of Australia - CSIRO, accessed July 30, 2025, Government

Soil and Landscape Grid of Australia - CSIRO

View Source

Supporting Sources (4)

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

Soil and Landscape Grid National Soil Attribute Maps - pH (Water) (3" resolution) - Release 1. v2

Methodology Source Government

Soil and Landscape Grid National Soil Attribute Maps - pH (Water) (3" resolution) - Release 1. v2

View Source

Soil and Landscape Grid of Australia - CSIRO

Direct Evidence Government

Soil and Landscape Grid National Soil Attribute Maps - pH - Calcium Chloride (3" resolution) - Release 2 - TERN Data Discovery Portal

View Source

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

Contextual Support Journal

Soil pH Explained - Soil Quality Knowledge Base

View Source

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Conservation / Protected Natural Areas
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 9 Jun 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. This value signifies a state of high ecological health and reflects the naturally neutral-to-alkaline soils shaped by the semi-arid climate and calcareous geology.

Related Benchmarks

Other benchmarks in the AUS-TSW-CON-SPH family.