Soil Structure & Compaction

AUS-TMS-AGR-SSC General Moderate confidence

Benchmark Value

1500 kPa

Thresholds: Lower: —, Upper: 3000

Direction: Lower is desirable ↓

Form: MinimumOnly

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 17 benchmarks together — the OptimalRange form drives the primary score, while 16 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MaximumOnly Guard MaximumOnly Guard LowerThreshold Guard UpperThreshold Guard Point Guard MaximumOnly Guard Point Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard MinimumOnly Guard OptimalRange Guard LowerThreshold Guard MaximumOnly Guard MinimumOnly Guard

Evidence & Context

A critical upper threshold for compaction, severely limiting root growth, is widely recognized at approximately 3000 kPa.

Metric Definition:

Penetrometer resistance (PR) threshold beyond which root growth is severely impeded

Benchmark Definition:

This benchmark represents a critical soil compaction threshold measured by penetrometer resistance, beyond which root growth is severely limited in tropical monsoonal savanna agricultural crop production.

Justification:

This threshold is based on foundational research and is broadly accepted as a point where mechanical impedance becomes a major limiting factor for root elongation and proliferation.

Sources (1)

Time-dependent changes in distribution patterns of soil bulk density ...

Time-dependent changes in distribution patterns of soil bulk density ...

View Source

Supporting Sources (12)

Additional references from the underlying research that informed this benchmark.

(PDF) Changes in surface soil properties of a no-tilled tropical Alfisol ...

Direct Evidence

(PDF) Changes in surface soil properties of a no-tilled tropical Alfisol ...

View Source

(PDF) Final report Scoping Study of Soil Management in Livestock Grazing Systems

Contextual Support Journal

Final report - MLA

View Source

Agricultural soils mitigate CO2 emissions - cifor-icraf

Contextual Support

Agricultural soils mitigate CO2 emissions - cifor-icraf

View Source

Bibliographies: 'Soil physical properties' - Grafiati

Contextual Support GreyLiterature

Bibliographies: 'Soil physical properties' - Grafiati

View Source

Preview of Carbon accounting, land management, science and policy uncertainty in Australian savanna landscapes: introduction and overview - ResearchGate

Carbon accounting, land management, science and policy uncertainty in Australian savanna landscapes: introduction and overview - ResearchGate

Contextual Support Journal

Soil carbon density can increase when Australian savanna is converted to pasture, but may not change under intense cropping systems | Request PDF - ResearchGate

View Source

Decomposition of crop residues under conventional and zero tillage - ResearchGate

Contextual Support Journal

Decomposition of crop residues under conventional and zero tillage - ResearchGate

View Source

Management of Soil Problems PDF - Scribd

Contextual Support

Management of Soil Problems PDF - Scribd

View Source

research.usq.edu.au

Contextual Support

research.usq.edu.au

View Source

SOILWATER CONSULTANTS - Deep Yellow, accessed July 27, 2025,

Contextual Support Journal

SECURING AUSTRALIA'S SOIL For profitable industries and healthy landscapes - DAFF

View Source

Sustainable land management for the Oxisols of the Latin American savannas - CGSpace

Contextual Support

Sustainable land management for the Oxisols of the Latin American savannas - CGSpace

View Source

Preview of Use of deep-rooted tropical pastures to build-up an arable layer through improved soil properties of an Oxisol in the Eastern Plains (Llanos Orientales) of Colombia | Request PDF - ResearchGate

Use of deep-rooted tropical pastures to build-up an arable layer through improved soil properties of an Oxisol in the Eastern Plains (Llanos Orientales) of Colombia | Request PDF - ResearchGate

Contextual Support GreyLiterature

Use of deep-rooted tropical pastures to build-up an arable layer through improved soil properties of an Oxisol in the Eastern Plains (Llanos Orientales) of Colombia | Request PDF - ResearchGate

View Source

www.frontiersin.org, accessed May 16, 2025,

Direct Evidence Journal

www.frontiersin.org

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 21 Mar 2026

Notes

Values approaching or exceeding this threshold indicate severely degraded soil health with significant negative consequences for crop productivity and ecological functioning. ConsistencyResolver applied 2026-03-23 00:15 UTC: BenchmarkValue 3000 → (check: MinAboveOptimalHigh, rationale: BenchmarkValue should be cleared or ignored when UpperThreshold is set to avoid confusion; however, since the system uses threshold fields primarily, no explicit change is proposed here.) ConsistencyResolver applied 2026-03-23 00:15 UTC: UpperThreshold → 3000 (check: MinAboveOptimalHigh, rationale: The Notes state 'Values approaching or exceeding this threshold indicate severely degraded soil health,' indicating this is an upper degradation limit. Moving the threshold to UpperThreshold will auto-correct the form to MaximumOnly, resolving the contradiction without duplicating the existing MaximumOnly benchmark.) ConsistencyResolver applied 2026-03-23 00:15 UTC: LowerThreshold → (check: MinAboveOptimalHigh, rationale: Clear LowerThreshold is null, no change needed here.) ConsistencyResolver applied 2026-03-23 00:15 UTC: BenchmarkValue 3000 → 1500 (check: MinAboveMax, rationale: Swapping values to reflect that 1500 kPa is the lower threshold (MinimumOnly) below which soil is considered healthy, consistent with the OptimalRange and Notes.)

Related Benchmarks

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