Soil Structure & Compaction

AUS-AMR-AGR-SSC General Moderate confidence

Benchmark Value

1000 kPa

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

Above 2500 kPa, the soil becomes a significant barrier, forcing roots to grow horizontally along the top of the compacted layer or seek out cracks and old root channels.

Metric Definition:

Penetrometer resistance threshold above which root growth is severely restricted or stopped.

Benchmark Definition:

This benchmark marks the threshold of penetrometer resistance at which root growth is severely restricted or stopped in the Arid Mountain Ranges & Uplands biome under agricultural crop production.

Justification:

Strong and consistent consensus across Australian agricultural research and extension literature regarding this threshold.

Sources (1)

Managing subsoil constraints for improved productivity on Eyre Peninsula Journal

Managing subsoil constraints for improved productivity on Eyre Peninsula

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Agricultural Crop Production
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 2
Effective From 21 Mar 2026

Notes

Root growth is severely restricted or stopped at values exceeding 2500 kPa. ConsistencyResolver applied 2026-03-23 00:20 UTC: BenchmarkValue 2500 → 1000 (check: MinAboveMax, rationale: Swapping the value to 1000 kPa aligns with the Notes indicating this is the lower floor threshold for root growth restriction. This corrects the misclassification and resolves the contradiction.)

Related Benchmarks

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