Soil Structure & Compaction

AUS-TMI-AGR-SSC General Moderate confidence

Benchmark Value

2000 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. The scoring engine uses 2 benchmarks together — the MaximumOnly form drives the primary score, while 1 guard(s) constrain the result.

Evidence & Context

Scientific literature consistently indicates that penetrometer resistance values exceeding 2,000 kPa significantly impede root growth for most crops.

Metric Definition:

Soil penetrometer resistance threshold above which root elongation is significantly restricted.

Benchmark Definition:

This benchmark defines the critical upper threshold of soil compaction measured by penetrometer resistance above which root growth and ecological function are significantly impaired in agricultural soils of this biome.

Justification:

Widely accepted conservative threshold where mechanical impedance significantly restricts root elongation for a broad range of agricultural crops.

Sources (1)

Preview of Soil Carbon Saturation: What Do We Really Know? - PMC - PubMed Central
Soil Carbon Saturation: What Do We Really Know? - PMC - PubMed Central

Root Penetration Is Associated with Root Diameter and Root Growth ...

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of Managing soils to keep them healthy and productive - MLA, accessed July 28, 2025,
Managing soils to keep them healthy and productive - MLA, accessed July 28, 2025,
Direct Evidence Journal

Soil Compaction Affects the Growth and Establishment of Street Trees in Urban Australia

View Source
Preview of Norfolk Island - Wikipedia, accessed July 30, 2025,
Norfolk Island - Wikipedia, accessed July 30, 2025,
Contextual Support

Norfolk Island - Wikipedia

View Source
Preview of Thornleigh Farm - Lord Howe Island
Thornleigh Farm - Lord Howe Island
Contextual Support

Thornleigh Farm - Lord Howe Island

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Maritime Islands
  • Land Use Agricultural Crop Production
  • Assessment Not Stated
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 2
  • Effective From 7 Jun 2026

Notes

Exceeding this threshold leads to reduced water and nutrient uptake, diminished carbon inputs, and decline in habitat quality for beneficial soil organisms. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

Other benchmarks in the AUS-TMI-AGR-SSC family.