Soil Electrical Conductivity (EC)

AUS-TMI-CON-SEC General Moderate confidence

Benchmark Value

0.15 dS/m

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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard MaximumOnly Guard OptimalRange Guard Point Guard MaximumOnly Guard OptimalRange Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard

Evidence & Context

The upper detrimental threshold is set at >0.4 dS/m (EC1:5). This value corresponds to the upper limit of the "Low" salinity class in the CSIRO Pacific Islands manual.

Metric Definition:

Soil Electrical Conductivity (EC1:5) measured in a 1:5 soil:water suspension

Benchmark Definition:

An electrical conductivity of 0.4 dS/m marks the upper detrimental threshold for soil salinity in conservation areas, indicating the onset of salt accumulation beyond natural leaching capacity.

Justification:

This threshold marks the transition from non-saline to slightly saline state, indicating stress to native flora and salt accumulation beyond natural leaching.

Sources (2)

Soil Analysis Methods and Results Interpretation ... - CSIRO Research Journal

Soil Analysis Methods and Results Interpretation ... - CSIRO Research

View Source

Preview of www.publications.qld.gov.au, accessed May 16, 2025,

www.publications.qld.gov.au, accessed May 16, 2025, Journal

Measuring soil salinity - The Australian Wine Research Institute

View Source

Supporting Sources (2)

Additional references from the underlying research that informed this benchmark.

Soil Research - CSIRO PUBLISHING, accessed May 16, 2025,

Contextual Support Journal

Litchfield Savanna BASE Contextual, Soil Physico-Chemical Data ...

View Source

Wet Tropics region GLM land types - FutureBeef

Contextual Support GreyLiterature

Wet Tropics region GLM land types - FutureBeef

View Source

Context

Region Australia
Biome Tropical & Subtropical Maritime Islands
Land Use Conservation / Protected Natural Areas
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 21 Mar 2026

Notes

Supported by international standards and Queensland government guides for soil salinity. ConsistencyResolver applied 2026-03-23 00:16 UTC: BenchmarkValue 0.4 → 0.15 (check: MinAboveMax, rationale: Swapping the MinimumOnly BenchmarkValue from 0.4 to 0.15 aligns with the MaximumOnly threshold's previous value, resolving the contradiction and maintaining unique forms.)

Related Benchmarks

Other benchmarks in the AUS-TMI-CON-SEC family.