Soil pH

AUS-TDG-LVG-SPH General Moderate confidence

Benchmark Value

No specific value — see range
Range: 5 to 5.5 pH
Optimal Range: 5 to 5.5
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 3 benchmarks together — the OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Evidence & Context

The proposed benchmark for soil pH(CaCl₂) is a range of 5.0 – 5.5. This is based on mean topsoil pH values observed in open inter-tree areas (5.01) and beneath tree canopies (5.50) in little-grazed, high-conservation-value temperate grassy woodlands in central New South Wales.

Metric Definition:

Topsoil pH measured in 0.01 M calcium chloride (CaCl₂) solution, representing soil acidity/alkalinity affecting ecosystem health.

Justification:

Based on measurements from little-grazed remnants representing high environmental health and ecological function, supported by Prober et al. (2002).

Sources (1)

Preview of Prober, S. M., Lunt, I. D., & Thiele, K. R. (2002). Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants. Australian Journal of Botany, 50(6), 687–697.
Prober, S. M., Lunt, I. D., & Thiele, K. R. (2002). Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants. Australian Journal of Botany, 50(6), 687–697. Journal

Prober, S.M., Thiele, K.R. and Lunt, I.D. (2002). Determining reference conditions for management and restoration of temperate grassy woodlands: relationships among trees, topsoils and understorey flora in little-grazed remnants. Australian Journal of Botany, 50(6), 687-697.

View Source

Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

Preview of Agriculture Victoria. (2024). Soil acidity.
Agriculture Victoria. (2024). Soil acidity.
Contextual Support Government

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

View Source
Preview of Government of South Australia, Department for Environment and Water. (n.d.). Soil Health and Condition.
Government of South Australia, Department for Environment and Water. (n.d.). Soil Health and Condition.
Contextual Support Government

Soil acidity - Department for Environment and Water

View Source
Preview of Manage soil acidity | EverGraze More livestock from perennials
Manage soil acidity | EverGraze More livestock from perennials
Contextual Support GreyLiterature

Manage soil acidity | EverGraze More livestock from perennials, accessed July 18, 2025,

View Source
Preview of Soil Quality Knowledge Base. (n.d.). Soil pH.
Soil Quality Knowledge Base. (n.d.). Soil pH.
Contextual Support GreyLiterature

Soil Quality Knowledge Base. (n.d.). Soil pH.

View Source

Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Livestock Grazing & Pasture
  • Assessment Pristine Reference
  • Vegetation Woodland
  • 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. The benchmark reflects spatial heterogeneity with distinct values under tree canopies and open areas, representing a natural range in healthy ecosystems.