Soil pH — Benchmark Detail

Benchmark Value

7.5 pH

Range: 6.8 to 8.2 pH

Thresholds: Lower: 5.7, Upper: —

Optimal Range: 6.8 to 8.2

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 8 benchmarks together — the OptimalRange form drives the primary score, while 7 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MinimumOnly Guard OptimalRange Guard OptimalRange Guard LowerThreshold Guard UpperThreshold 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:

This benchmark represents the typical soil pH in protected natural areas of the Australian Temperate Semi-Arid Shrublands & Open Woodlands, reflecting naturally neutral to alkaline soils under conservation management.

Justification:

The confidence in this benchmark is rated as High due to the comprehensive, consistent, nationally standardized, and scientifically validated Soil and Landscape Grid of Australia data, representing millions of data points across the biome's protected natural areas.

Sources (3)

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

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

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

View Source

Soil and Landscape Grid National Soil Attribute Maps - pH (Water) (3" resolution) - Release 1. v2 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, accessed July 30, 2025,

Soil and Landscape Grid of Australia - CSIRO, accessed August 1, 2025

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

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

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 24 Mar 2026

Notes

Lower Critical Threshold: 5.7 pH. Optimal range: 6.8 to 8.2 pH. No simple upper detrimental threshold; values above 8.5 may indicate sodicity and require further assessment.

Related Benchmarks

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