Soil Structure & Compaction

AUS-TDG-CON-SSC General High confidence

Benchmark Value

1000 kPa
Direction: Lower is desirable ↓
Form: MaximumOnly

Scoring Curve

This curve shows how a field measurement for this indicator would score across all available benchmark forms in this context.

Evidence & Context

Root growth is likely to be restricted by soil strengths greater than 1 MPa, and seedling emergence may be unsuccessful in soils between 1 and 2 MPa at field capacity, as resistance is likely to exceed 3 MPa before wilting point.

Metric Definition:

Soil penetration resistance (MPa) measured at 20% gravimetric water content (field capacity) using a needle penetrometer on reconstructed soil cores.

Benchmark Definition:

Degradation threshold for soil strength above which root growth restriction begins for Eucalyptus albens in temperate dry woodlands.

Justification:

This study directly tests the physiological response of the primary overstorey canopy species (Eucalyptus albens) of southeastern Australian dry temperate grassy woodlands to soil compaction, identifying the point where root development begins to decline.

Sources (1)

Preview of (PDF) The effect of soil compaction on germination and early growth ..., accessed August 4, 2025,
(PDF) The effect of soil compaction on germination and early growth ..., accessed August 4, 2025, Journal

The effect of soil compaction on germination and early growth of Eucalyptus albens and an exotic annual grass

View Source

Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

Preview of Changes to soil physical properties after grazing exclusion
Changes to soil physical properties after grazing exclusion
Irrelevant

Changes to soil physical properties after grazing exclusion

View Source
Preview of Compacted Soil as a Permeable Impediment
Compacted Soil as a Permeable Impediment
Contextual Support Journal

Compacted Soil as a Permeable Impediment

View Source
Preview of SOIL CARBON EDITION - North Central Catchment Management Authority, accessed July 28, 2025,
SOIL CARBON EDITION - North Central Catchment Management Authority, accessed July 28, 2025,
Direct Evidence Government

Detecting soil compaction

View Source
Preview of Soil penetration resistance and tree root development | Request PDF - ResearchGate, accessed May 16, 2025,
Soil penetration resistance and tree root development | Request PDF - ResearchGate, accessed May 16, 2025,
Direct Evidence Journal

Soil penetration resistance and tree root development

View Source

Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Vegetation Woodland
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 20 Jun 2026

Notes

At strengths above 1000 kPa, root depth declines linearly, leading to shallow lateral root systems that are highly susceptible to summer drought-induced desiccation.