Soil Potassium

AUS-TMS-FOR-SOK General Moderate confidence

Benchmark Value

50 mg/kg

Direction: Higher 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 2 benchmarks together — the OptimalRange form drives the primary score, while 1 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard

Evidence & Context

Lower Critical Threshold: <50 mg/kg. Soil K levels below this threshold are strongly associated with a high likelihood of K deficiency, impaired physiological function, and significantly reduced growth and vigor

Metric Definition:

available soil potassium

Benchmark Definition:

This benchmark defines the minimum critical threshold of available soil potassium below which there is a high risk of potassium deficiency and impaired plant growth in Tropical Monsoonal Savannas under production forestry.

Justification:

Consistent with native levels showing K limitation for plantations and aligns with 'Low' pasture status and crop deficiency thresholds.

Sources (2)

Soil Research - CSIRO PUBLISHING Journal

Soil Research - CSIRO PUBLISHING

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Preview of Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025

Understanding soil tests for pastures | Soil | Farm management ..., accessed May 12, 2025 Government

Agriculture Victoria. (2025). Understanding soil tests for pastures. Farm Management.

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Supporting Sources (6)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Soil potassium—crop response calibration relationships and criteria for field crops grown in Australia - ResearchGate, accessed July 18, 2025,

(PDF) Soil potassium—crop response calibration relationships and criteria for field crops grown in Australia - ResearchGate, accessed July 18, 2025,

Direct Evidence Journal

Nutrient Cycling in Australian Savannas on JSTOR - DOI

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Preview of Leaf-level photosynthetic capacity dynamics in relation to soil and foliar nutrients along forest–savanna boundaries in Ghana and Brazil | Tree Physiology | Oxford Academic

Leaf-level photosynthetic capacity dynamics in relation to soil and foliar nutrients along forest–savanna boundaries in Ghana and Brazil | Tree Physiology | Oxford Academic

Contextual Support Journal

Leaf-level photosynthetic capacity dynamics in relation to soil and foliar nutrients along forest–savanna boundaries in Ghana and Brazil | Tree Physiology | Oxford Academic

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Preview of Multiple soil element and pH interactions constrain plant performance on tropical soils with a long history of fire - CSIRO PUBLISHING | Soil Research, accessed May 16, 2025,

Multiple soil element and pH interactions constrain plant performance on tropical soils with a long history of fire - CSIRO PUBLISHING | Soil Research, accessed May 16, 2025,

Direct Evidence Journal

Soil Research - CSIRO PUBLISHING

View Source