Soil Potassium

AUS-TMS-AGR-SOK General Moderate confidence

Benchmark Value

No specific value — see range

Range: 70 to 120 mg/kg

Optimal Range: 70 to 120

Direction: Higher is desirable ↑

Form: OptimalRange

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 5 benchmarks together — the OptimalRange form drives the primary score, while 4 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary Point Guard MinimumOnly Guard MaximumOnly Guard Point Guard

Evidence & Context

The proposed benchmark for exchangeable potassium in the 0-10 cm soil depth is a range of 70 - 120 mg/kg.

Metric Definition:

Exchangeable potassium concentration in the 0-10 cm soil depth

Benchmark Definition:

A synthesized target range representing high environmental health and sustainable productivity for soil potassium in agricultural crop production systems in Australian Tropical Monsoonal Savannas.

Justification:

Derived from synthesis of native soil values, agronomic critical minimums, and principles of nutrient stewardship in the target biome.

Sources (2)

Fertilisation with P, N and S requires additional Zn for healthy plantation tree growth on low fertility savanna soils - ResearchGate Journal

Fertilisation with P, N and S requires additional Zn for healthy plantation tree growth on low fertility savanna soils - ResearchGate

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Preview of Soil potassium—crop response calibration relationships and ...

Soil potassium—crop response calibration relationships and ... Journal

Soil Survey of the Kurnturlpara Area, Warumungu Aboriginal Land Trust

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Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

Soil Research - CSIRO PUBLISHING

Contextual Support Journal

Soil Research - CSIRO PUBLISHING

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Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Agricultural Crop Production
Assessment Conservation Target
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 8 Jun 2026

Notes

This range is above native background levels (~46 mg/kg) and agronomic critical minimums (~49 mg/kg Colwell K), indicating sufficiency for robust plant growth. It is considered an aspirational yet achievable target for well-managed agricultural systems on typical savanna soils.

Related Benchmarks

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