Soil Phosphorus

AUS-TSR-LVG-SOP General High confidence

Benchmark Value

No specific value — see range

Range: 10 to 15 mg/kg

Thresholds: Lower: 6, Upper: 20

Optimal Range: 10 to 15

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.

Evidence & Context

Based on this synthesis, the proposed benchmark for a high-health, well-managed, mixed-species grazing system in the Australian tropical and subtropical rainforest biome is a Colwell-P range of 10–15 mg/kg for soils with low-to-moderate PBI.

Metric Definition:

Soil phosphorus concentration measured as Colwell-P test value in mg/kg.

Benchmark Definition:

The optimal range for plant-available phosphorus (Colwell-P test) for balancing productivity and ecological health in well-managed tropical/subtropical pastures on low-to-moderate Phosphorus Buffering Index (PBI) soils.

Justification:

This range is sufficient to support productive growth of introduced pasture species and nitrogen-fixing legumes, but remains below the critical 20 mg/kg threshold, thereby providing a greater opportunity to maintain a component of desirable, fertility-tolerant native grasses within the sward.

Sources (1)

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, GreyLiterature

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

Supporting Sources (21)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Comparing the effects of continuous and time-controlled grazing systems on soil characteristics in Southeast Queensland - ResearchGate, accessed July 19, 2025,

(PDF) Comparing the effects of continuous and time-controlled grazing systems on soil characteristics in Southeast Queensland - ResearchGate, accessed July 19, 2025,

Contextual Support

Phosphorus Distribution in Soils from Australian Dairy and Beef Rearing Pastoral Systems, accessed July 18, 2025,

Preview of ANIMAL SCIENCE IN AUSTRALIA, accessed July 28, 2025,

ANIMAL SCIENCE IN AUSTRALIA, accessed July 28, 2025,

Contextual Support GreyLiterature

Phosphorus supplementation of cattle in northern Australia - FutureBeef, accessed July 18, 2025,

Preview of Critical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials - BioOne Complete, accessed July 28, 2025,

Critical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials - BioOne Complete, accessed July 28, 2025,

Contextual Support Journal

Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA

Preview of Cycling of phosphorus in grazing systems - NSW Department of Primary Industries, accessed July 18, 2025,

Cycling of phosphorus in grazing systems - NSW Department of Primary Industries, accessed July 18, 2025,

Contextual Support GreyLiterature

Cycling of phosphorus in grazing systems - NSW Department of Primary Industries, accessed July 18, 2025,

Preview of Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed August 5, 2025,

Do regenerative grazing management practices improve vegetation and soil health in grazed rangelands? Preliminary insights from a space-for-time study in the Great Barrier Reef catchments, Australia - CSIRO Publishing, accessed August 5, 2025,

Contextual Support

Ludwig, J.A., Bastin, G.N., Chewings, V.H., Eager, R.W., and Liedloff, A.C. (2005). Clearing savannas for use as rangelands in Queensland: Altered landscapes and water-erosion processes. Rangeland Journal, 27(2), 135-149.

Preview of Evidence of Large-Scale Chronic Eutrophication in the Great Barrier Reef: Quantification of Chlorophyll a Thresholds for Sustaining Coral Reef Communities - PubMed Central, accessed August 1, 2025

Evidence of Large-Scale Chronic Eutrophication in the Great Barrier Reef: Quantification of Chlorophyll a Thresholds for Sustaining Coral Reef Communities - PubMed Central, accessed August 1, 2025

Contextual Support Journal

Sediments and nutrients in north Queensland tropical streams: changes with agricultural development and pristine condition status, accessed July 18, 2025,

Preview of Grassed up - Introduction - NSW Department of Primary Industries, accessed August 5, 2025,

Grassed up - Introduction - NSW Department of Primary Industries, accessed August 5, 2025,

Contextual Support

Why phosphorus is important - NSW Department of Primary Industries, accessed July 18, 2025,

Preview of Improved maps of available phosphorus for the state of Queensland ..., accessed July 17, 2025,

Improved maps of available phosphorus for the state of Queensland ..., accessed July 17, 2025,

Contextual Support Journal

Updating the Phosphorus Map of Queensland - FutureBeef, accessed July 18, 2025,

Preview of Indicative Soil Phosphorus Report | LongPaddock | Queensland Government

Indicative Soil Phosphorus Report | LongPaddock | Queensland Government

Contextual Support Government

Indicative Soil Phosphorus Report | LongPaddock | Queensland Government, accessed August 1, 2025

Preview of Loss of phosphorus and nitrogen in runoff and subsurface drainage from high and low input pastures grazed by sheep in southern Australia - ResearchGate, accessed July 18, 2025,

Loss of phosphorus and nitrogen in runoff and subsurface drainage from high and low input pastures grazed by sheep in southern Australia - ResearchGate, accessed July 18, 2025,

Contextual Support Journal

Loss of phosphorus and nitrogen in runoff and subsurface drainage from high and low input pastures grazed by sheep in southern Australia - ResearchGate, accessed July 18, 2025,

Preview of Nutrient loss and water quality under extensive grazing in the upper ...

Nutrient loss and water quality under extensive grazing in the upper ...

Contextual Support Journal

Evidence of Large-Scale Chronic Eutrophication in the Great Barrier Reef: Quantification of Chlorophyll a Thresholds for Sustaining Coral Reef Communities - PubMed Central, accessed July 18, 2025,

Preview of Nutrient loss and water quality under extensive grazing in the upper Burdekin river catchment, North Queensland, accessed July 18, 2025,

Nutrient loss and water quality under extensive grazing in the upper Burdekin river catchment, North Queensland, accessed July 18, 2025,

Contextual Support Government

Catchment care - Queensland Environment Department, accessed July 18, 2025,

Preview of Phosphorus - WA | Fact Sheets | soilquality.org.au, accessed July 21, 2025,

Phosphorus - WA | Fact Sheets | soilquality.org.au, accessed July 21, 2025,

Contextual Support GreyLiterature

Phosphorus - Qld | Fact Sheets | soilquality.org.au, accessed July 18, 2025,

Preview of Phosphorus fertiliser management for pastures ... - CSIRO Publishing, accessed August 11, 2025

Phosphorus fertiliser management for pastures ... - CSIRO Publishing, accessed August 11, 2025

Contextual Support Journal

Phosphorus fertiliser management for pastures ... - CSIRO Publishing

Preview of Phosphorus fertiliser management for pastures based on native grasses in south-eastern Australia - ResearchGate, accessed July 18, 2025,

Phosphorus fertiliser management for pastures based on native grasses in south-eastern Australia - ResearchGate, accessed July 18, 2025,

Contextual Support Journal

Soil phosphorus and tree cover modify the effects of livestock grazing on plant species richness in Australian grassy woodland - ResearchGate, accessed August 5, 2025,

Preview of Phosphorus for high rainfall pastures - DPIRD's Digital library, accessed July 23, 2025,

Phosphorus for high rainfall pastures - DPIRD's Digital library, accessed July 23, 2025,

Contextual Support

Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed July 18, 2025,

Preview of Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed August 4, 2025

Phosphorus Nutrition of Proteaceae in Severely Phosphorus-Impoverished Soils: Are There Lessons To Be Learned for Future Crops? - PubMed Central, accessed August 4, 2025

Contextual Support Journal

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC

Preview of Soil nutrient critical limits | MBFP | More Beef from Pastures, accessed July 18, 2025,

Soil nutrient critical limits | MBFP | More Beef from Pastures, accessed July 18, 2025,

Contextual Support

How Much Phosphorus Do We Want in Our Soils? - On Pasture, accessed July 18, 2025,

Preview of Tropical Pasture - Barenbrug Australia, accessed July 18, 2025,

Tropical Pasture - Barenbrug Australia, accessed July 18, 2025,

Contextual Support Journal

Soils of the Koolpinyah Surface (Chen et al., 2005)

Preview of What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase, accessed August 5, 2025,

Contextual Support Government

Scanlan, C. A., et al. (2013). Soil Quality: 10 Plant Nutrition. CCMA Soil Health Knowledge Base.

Preview of www.rrrc.org.au, accessed May 15, 2025,

www.rrrc.org.au, accessed May 15, 2025,

Contextual Support Journal

Sediments and nutrients in north Queensland tropical streams: changes with agricultural development and pristine condition status (Technical Report No. 62, Australian Rainforest CRC, 2006)

Context

Region Australia
Biome Tropical & Subtropical Rainforests
Land Use Livestock Grazing & Pasture
Assessment Pristine Reference
Evidence Type TargetCondition

Lifecycle

Status Active
Version 1
Effective From 24 Mar 2026

Notes

Lower Critical Threshold: <6 mg/kg is deficient, compromising animal health and pasture persistence. Upper Detrimental Threshold: Levels >20 mg/kg lead to significant loss of native grass biodiversity and increased risk of phosphorus loss in runoff contributing to eutrophication.