Soil Potassium

AUS-TGP-CON-SOK General Moderate confidence

Benchmark Value

No specific value — see range
Range: 161 to 250 mg/kg
Optimal Range: 161 to 250
Direction: Higher is desirable ↑
Form: StratifiedVariant

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 3 benchmarks together — the MinimumOnly form drives the primary score, while 2 guard(s) constrain the result.

Contributing Benchmarks

MinimumOnly Primary StratifiedVariant Guard MaximumOnly Guard

Evidence & Context

The recommended benchmark for a high-health conservation site represents a state of nutrient sufficiency for the diverse native understorey, not nutrient enrichment. It is positioned at the transition between the "Moderate" and "Ideal" agronomic ranges, providing enough potassium to support key functional groups like native legumes and forbs without creating conditions that favour invasive species.

Metric Definition:

Available soil potassium (K) measured by the Colwell K soil test, representing nutrient sufficiency for native biodiversity in conservation contexts.

Benchmark Definition:

The ecologically optimal range of available soil potassium for high-integrity conservation areas in clay loam soils.

Justification:

Derived by re-interpreting agronomic 'Ideal' targets through an ecological lens to avoid nutrient enrichment that favors invasive species.

Sources (1)

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.

View Source

Supporting Sources (32)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Determining reference conditions for management and ..., accessed August 5, 2025,
(PDF) Determining reference conditions for management and ..., accessed August 5, 2025,
Contextual Support Journal

Effects of Stock Grazing on Biodiversity Values in Temperate Native Grasslands and Grassy Woodlands in SE Australia: A Literature Review - ACT Government

View Source
Preview of Approved Conservation Advice for the White Box - Yellow Box - Blakely's Red Gum Grassy Woodland and Derived Native Grassland - DCCEEW, accessed August 12, 2025,
Approved Conservation Advice for the White Box - Yellow Box - Blakely's Red Gum Grassy Woodland and Derived Native Grassland - DCCEEW, accessed August 12, 2025,
Contextual Support Journal

Conservation Advice for Lowland Grassy Woodland in the South East Corner Bioregion

View Source
Preview of Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 5, 2025,
Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed August 5, 2025,
Contextual Support Journal

How should we manage our soils to increase soil carbon?, accessed May 10, 2026

View Source
Preview of Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London, accessed August 11, 2025,
Comment: Potassium in soil is running low, threatening global food security - study proposes way out | UCL News - UCL – University College London, accessed August 11, 2025,
Contextual Support GreyLiterature

Living with high potassium: Balance between nutrient acquisition and K-induced salt stress signaling

View Source
Preview of Ecology of Australia: the effects of nutrient-poor soils and intense fires - PubMed, accessed August 11, 2025,
Ecology of Australia: the effects of nutrient-poor soils and intense fires - PubMed, accessed August 11, 2025,
Contextual Support Journal

A Study on Distribution of Forms of Phosphorus in Calcareous Soils ..., accessed July 22, 2025

View Source
Preview of Environment - Restore Trees NSW, accessed August 11, 2025,
Environment - Restore Trees NSW, accessed August 11, 2025,
Contextual Support Government

Environment - Restore Trees NSW, accessed August 11, 2025,

View Source
Preview of Eucalyptus recruitment in degraded woodlands: no benefit from elevated soil fertility, accessed August 11, 2025,
Eucalyptus recruitment in degraded woodlands: no benefit from elevated soil fertility, accessed August 11, 2025,
Contextual Support

Eucalyptus recruitment in degraded woodlands: no benefit from elevated soil fertility, accessed August 11, 2025,

View Source
Preview of Grasslands and Grassy Woodlands of the VVP: Landholders Guide - Greening Australia, accessed August 11, 2025,
Grasslands and Grassy Woodlands of the VVP: Landholders Guide - Greening Australia, accessed August 11, 2025,
Contextual Support Journal

www.greeningaustralia.org.au, accessed May 17, 2025

View Source
Preview of Grassy woodlands | Landscape Australia, accessed August 5, 2025,
Grassy woodlands | Landscape Australia, accessed August 5, 2025,
Contextual Support GreyLiterature

Grassy woodlands | Landscape Australia, accessed August 4, 2025,

View Source
Preview of Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia, accessed August 10, 2025,
Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia, accessed August 10, 2025,
Contextual Support

Is there a close association between 'soils' and 'vegetation'? A case study from central western New South Wales, accessed August 4, 2025,

View Source
Preview of Identification Guidelines for Endangered Ecological Communities: White box - yellow box - Blakely's red gum woodland - NSW Environment Protection Authority, accessed August 11, 2025,
Identification Guidelines for Endangered Ecological Communities: White box - yellow box - Blakely's red gum woodland - NSW Environment Protection Authority, accessed August 11, 2025,
Contextual Support Journal

Identification Guidelines for Endangered Ecological Communities: White box - yellow box - Blakely's red gum woodland - NSW Environment Protection Authority, accessed August 11, 2025,

View Source
Preview of Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states - ResearchGate, accessed August 5, 2025,
Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states - ResearchGate, accessed August 5, 2025,
Contextual Support GreyLiterature

(PDF) Identifying ecological barriers to restoration in temperate grassy woodlands: soil changes associated with different degradation states - ResearchGate, accessed August 4, 2025,

View Source
Preview of Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain p - BioOne Complete, accessed August 11, 2025,
Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain p - BioOne Complete, accessed August 11, 2025,
Contextual Support Journal

Long-term rundown of plant-available potassium in Western Australia requires a re-evaluation of potassium management for grain p - BioOne Complete, accessed August 11, 2025,

View Source
Preview of Multiple adaptive responses of Australian native perennial legumes with pasture potential to grow in phosphorus- and moisture-limited environments, accessed August 11, 2025,
Multiple adaptive responses of Australian native perennial legumes with pasture potential to grow in phosphorus- and moisture-limited environments, accessed August 11, 2025,
Contextual Support Journal

Multiple adaptive responses of Australian native perennial legumes with pasture potential to grow in phosphorus- and moisture-limited environments, accessed July 16, 2025,

View Source
Preview of National Soil Action Plan - DAFF, accessed August 11, 2025,
National Soil Action Plan - DAFF, accessed August 11, 2025,
Contextual Support Journal

Australian Government. (2023). National Soil Action Plan 2023 to 2028. Department of Agriculture, Fisheries and Forestry.

View Source
Preview of Natural Temperate Grassland of the Southern Tablelands of NSW and the Australian Capital Territory. - DCCEEW, accessed August 12, 2025,
Natural Temperate Grassland of the Southern Tablelands of NSW and the Australian Capital Territory. - DCCEEW, accessed August 12, 2025,
Contextual Support Government

NVIS Fact sheet MVG 19  Tussock grasslands, accessed August 6, 2025

View Source
Preview of NVIS Fact sheet MVG 19 6 Tussock grasslands, accessed July 16, 2025,
NVIS Fact sheet MVG 19 6 Tussock grasslands, accessed July 16, 2025,
Contextual Support Journal

Understanding soil pH, accessed August 28, 2025

View Source
Preview of Overcoming restoration thresholds and increasing revegetation success for a range of canopy species in a degraded urban Mediterranean-type woodland ecosystem - CSIRO PUBLISHING | Australian Journal of Botany, accessed August 11, 2025,
Overcoming restoration thresholds and increasing revegetation success for a range of canopy species in a degraded urban Mediterranean-type woodland ecosystem - CSIRO PUBLISHING | Australian Journal of Botany, accessed August 11, 2025,
Contextual Support Journal

Overcoming restoration thresholds and increasing revegetation success for a range of canopy species in a degraded urban Mediterranean-type woodland ecosystem - CSIRO PUBLISHING | Australian Journal of Botany, accessed August 11, 2025,

View Source
Preview of Patterns in potassium dynamics in forest ecosystems - PubMed, accessed August 11, 2025,
Patterns in potassium dynamics in forest ecosystems - PubMed, accessed August 11, 2025,
Contextual Support Journal

Soil Fertility (Part III) - Properties and Management of Soils in the Tropics

View Source
Preview of Potassium | Fact Sheets | soilquality.org.au, accessed August 11, 2025,
Potassium | Fact Sheets | soilquality.org.au, accessed August 11, 2025,
Contextual Support Government

Potassium | Fact Sheets | soilquality.org.au

View Source
Preview of Potassium Control of Plant Functions: Ecological and Agricultural Implications - MDPI, accessed August 11, 2025,
Potassium Control of Plant Functions: Ecological and Agricultural Implications - MDPI, accessed August 11, 2025,
Contextual Support Journal

Potassium Control of Plant Functions: Ecological and Agricultural Implications - MDPI

View Source
Preview of Potassium for high-performing pastures | Nutrient Advantage, accessed July 18, 2025,
Potassium for high-performing pastures | Nutrient Advantage, accessed July 18, 2025,
Contextual Support Journal

Potassium for high rainfall pastures - DPIRD's Digital library

View Source
Preview of Potassium In Soil Explained - Soil Quality Knowledge Base, accessed August 11, 2025,
Potassium In Soil Explained - Soil Quality Knowledge Base, accessed August 11, 2025,
Contextual Support GreyLiterature

Healthy soils and soil test interpretation - North Central Catchment Management Authority

View Source
Preview of Protecting Critically Endangered Grasslands | Victorian Auditor-General's Office, accessed August 10, 2025
Protecting Critically Endangered Grasslands | Victorian Auditor-General's Office, accessed August 10, 2025
Contextual Support Government

Protecting native grasses – ANU Sustainable Farms, accessed August 11, 2025

View Source
Preview of Should I Fertilise Australian Native Plants? - Natural Growth Institute, accessed August 11, 2025,
Should I Fertilise Australian Native Plants? - Natural Growth Institute, accessed August 11, 2025,
Contextual Support GreyLiterature

Should I Fertilise Australian Native Plants? - Natural Growth Institute, accessed August 11, 2025,

View Source
Preview of Soil biodiversity | Land and soil - Environment and Heritage - NSW Government, accessed August 11, 2025,
Soil biodiversity | Land and soil - Environment and Heritage - NSW Government, accessed August 11, 2025,
Contextual Support Government

Soil biodiversity | Land and soil - Environment and Heritage - NSW Government, accessed August 11, 2025,

View Source
Preview of Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025,
Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA, accessed May 13, 2025,
Contextual Support Government

Understanding soil tests for pastures | Soil | Farm management ..., accessed July 17, 2025

View Source
Preview of Soil Research - CSIRO PUBLISHING
Soil Research - CSIRO PUBLISHING
Contextual Support Journal

Soil Research - CSIRO PUBLISHING

View Source
Preview of Towards restoration of grassy White and Yellow Box woodlands ..., accessed August 11, 2025,
Towards restoration of grassy White and Yellow Box woodlands ..., accessed August 11, 2025,
Contextual Support GreyLiterature

(PDF) Soil and vegetation response to thinning White Cypress Pine ...

View Source
Preview of V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing, accessed August 11, 2025,
V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing, accessed August 11, 2025,
Contextual Support Journal

V*. Clearing and burning brigalow (Acacia harpophylla) in Queensland, Australia, temporarily increases surface soil fertility prior to nutrient decline under cropping or grazing - CSIRO Publishing, accessed July 18, 2025,

View Source
Preview of White Box Yellow Box Blakely's Red Gum Woodland - Determination to make a minor amendment to Part 3 of Schedule 1 of the Threatened Species Conservation Act - Environment and Heritage, accessed August 11, 2025,
White Box Yellow Box Blakely's Red Gum Woodland - Determination to make a minor amendment to Part 3 of Schedule 1 of the Threatened Species Conservation Act - Environment and Heritage, accessed August 11, 2025,
Contextual Support Regulatory Framework Government

White Box Yellow Box Blakely's Red Gum Woodland - Determination to make a minor amendment to Part 3 of Schedule 1 of the Threatened Species Conservation Act - Environment and Heritage, accessed August 11, 2025,

View Source
Preview of Woodlands - DCCEEW, accessed August 5, 2025,
Woodlands - DCCEEW, accessed August 5, 2025,
Contextual Support Government

Woodlands - DCCEEW, accessed August 4, 2025,

View Source

Context

  • Region Australia
  • Biome Temperate Grassy Woodlands & Plains
  • Land Use Conservation / Protected Natural Areas
  • Assessment Conservation Target
  • Evidence Type ReferenceCondition

Lifecycle

  • Status Active
  • Version 1
  • Effective From 1 Jun 2026

Notes

This range reflects values sufficient for native biodiversity without promoting invasive species.

Related Benchmarks

Other benchmarks in the AUS-TGP-CON-SOK family.

— mg/kg Moderate
Conservation / Protected Natural Areas · Conservation Target
StratifiedVariant Active v1
80 mg/kg Moderate
Conservation / Protected Natural Areas · Conservation Target
MinimumOnly Active v1
110 mg/kg Moderate
Conservation / Protected Natural Areas · Conservation Target
MinimumOnly Active v1
200 mg/kg Moderate
Conservation / Protected Natural Areas · Conservation Target
MaximumOnly Active v1
250 mg/kg Moderate
Conservation / Protected Natural Areas · Conservation Target
MaximumOnly Active v1