Fungal:Bacterial Ratio

AUS-AKW-AGR-SFB General Moderate confidence

Benchmark Value

2 index
Thresholds: Lower: —, Upper: 2
Direction: Higher is desirable ↑
Form: MaximumOnly

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 OptimalRange form drives the primary score, while 2 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary LowerThreshold Guard MaximumOnly Guard

Evidence & Context

An F:B ratio > 2.0 is considered agronomically undesirable for most annual/perennial cropping systems, as it indicates a shift to a late-successional, forest-like soil environment.

Metric Definition:

Upper boundary of F:B ratio indicating functional mismatch for cropping systems

Benchmark Definition:

This benchmark defines the upper detrimental threshold of fungal to bacterial biomass ratio beyond which soil function is mismatched to cropping system needs in Australia's Arid Karstic Woodlands & Shrublands.

Justification:

This is not due to ecological degradation but rather a functional mismatch, where the soil's slow, nutrient-immobilizing characteristics become more suited to late-successional vegetation than to annual crops.

Sources (1)

Preview of Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central, accessed July 18, 2025
Biogeographical patterns of the soil fungal:bacterial ratio across France - PubMed Central, accessed July 18, 2025 Journal

Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 23, 2025

View Source

Supporting Sources (24)

Additional references from the underlying research that informed this benchmark.

Preview of Analyzing your Fungal to Bacterial Ratio Results - MicroBiometer, accessed July 18, 2025
Analyzing your Fungal to Bacterial Ratio Results - MicroBiometer, accessed July 18, 2025
Methodology Source GreyLiterature

Analyzing your Fungal to Bacterial Ratio Results - microBIOMETER, accessed June 7, 2025,

View Source
Preview of Are Fungal to Bacterial Ratios (F:B Ratio) Important for Plant Growth? - Garden Myths, accessed July 23, 2025,
Are Fungal to Bacterial Ratios (F:B Ratio) Important for Plant Growth? - Garden Myths, accessed July 23, 2025,
Contextual Support Journal

FARMER'S TOOLBOX - Panda.org, accessed July 23, 2025,

View Source
Preview of ausveg - fact sheet: soil microbiology, accessed July 18, 2025
ausveg - fact sheet: soil microbiology, accessed July 18, 2025
Contextual Support Journal

ausveg - fact sheet: soil microbiology

View Source
Preview of Biogeographical patterns of the soil fungal:bacterial ratio across France - ASM Journals, accessed July 28, 2025
Biogeographical patterns of the soil fungal:bacterial ratio across France - ASM Journals, accessed July 28, 2025
Contextual Support Journal

Beyond Bacteria: The Importance of Fungi, Protozoa and Nematodes in Soil Microbiology, accessed July 21, 2025

View Source
Preview of Calcareous Soils Initiative - GRDC, accessed July 22, 2025,
Calcareous Soils Initiative - GRDC, accessed July 22, 2025,
Contextual Support Government

Calcareous Soils Initiative - GRDC, accessed July 24, 2025

View Source
Preview of Climate dictates microbial community composition and diversity in Australian biological soil crusts (biocrusts) - PMC - PubMed Central, accessed July 23, 2025,
Climate dictates microbial community composition and diversity in Australian biological soil crusts (biocrusts) - PMC - PubMed Central, accessed July 23, 2025,
Contextual Support Journal

Assembly and Source of the Lithobiontic Microbial Community in Limestone - MDPI, accessed July 23, 2025,

View Source
Preview of Comparison of methods for assessing fungi-to-bacteria ratio of soil - ResearchGate, accessed on June 5, 2025
Comparison of methods for assessing fungi-to-bacteria ratio of soil - ResearchGate, accessed on June 5, 2025
Methodology Source Journal

Comparison of methods for assessing fungi-to-bacteria ratio of soil - ResearchGate, accessed July 23, 2025,

View Source
Preview of Contrasting Soil pH Effects on Fungal and Bacterial Growth Suggest Functional Redundancy in Carbon Mineralization - PMC, accessed July 23, 2025,
Contrasting Soil pH Effects on Fungal and Bacterial Growth Suggest Functional Redundancy in Carbon Mineralization - PMC, accessed July 23, 2025,
Contextual Support Journal

Contrasting Soil pH Effects on Fungal and Bacterial Growth Suggest Functional Redundancy in Carbon Mineralization - PMC, accessed July 23, 2025,

View Source
Preview of Effects of Semiarid Wheat Agriculture Management Practices on Soil ..., accessed August 5, 2025,
Effects of Semiarid Wheat Agriculture Management Practices on Soil ..., accessed August 5, 2025,
Contextual Support

Effects of Semiarid Wheat Agriculture Management Practices on Soil Microbial Properties: A Review - MDPI, accessed July 23, 2025,

View Source
Preview of Fungal to Bacterial Ratios: What and Why? - Ward Laboratories, Inc., accessed July 18, 2025
Fungal to Bacterial Ratios: What and Why? - Ward Laboratories, Inc., accessed July 18, 2025
Contextual Support GreyLiterature

Fungal/bacterial ratios in grasslands with contrasting nitrogen management, accessed July 30, 2025,

View Source
Preview of Fungal/bacterial ratios in grasslands with contrasting nitrogen management - ResearchGate, accessed July 18, 2025
Fungal/bacterial ratios in grasslands with contrasting nitrogen management - ResearchGate, accessed July 18, 2025
Contextual Support Journal

Adaptive multi-paddock grazing increases soil nutrient availability and bacteria to fungi ratio in grassland soils | Request PDF - ResearchGate, accessed August 9, 2025,

View Source
Preview of How microbial C/N and organic C/N ratio relate ? | ResearchGate, accessed July 18, 2025,
How microbial C/N and organic C/N ratio relate ? | ResearchGate, accessed July 18, 2025,
Contextual Support GreyLiterature

The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil, accessed July 23, 2025,

View Source
Preview of Impact of Rocky Desertification Control on Soil Bacterial Community in Karst Graben Basin, Southwestern China - Frontiers, accessed July 23, 2025,
Impact of Rocky Desertification Control on Soil Bacterial Community in Karst Graben Basin, Southwestern China - Frontiers, accessed July 23, 2025,
Contextual Support Journal

Aridity Threshold Induces Abrupt Change of Soil Abundant and Rare Bacterial Biogeography in Dryland Ecosystems - PMC - PubMed Central, accessed July 29, 2025

View Source
Preview of Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 18, 2025
Mechanisms and implications of bacterial–fungal competition for soil resources - PMC, accessed July 18, 2025
Contextual Support Journal

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling - Frontiers, accessed July 23, 2025

View Source
Preview of Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025
Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed August 4, 2025
Contextual Support Journal

NCC: Regenerative Agriculture and Soil Health - Wet Tropics Plan, accessed July 27, 2025,

View Source
Preview of Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed July 23, 2025,
Regenerative agriculture in Australia: the changing face of farming - Frontiers, accessed July 23, 2025,
Contextual Support Journal

Soil Properties Regulate Soil Microbial Communities During Forest Succession in a Karst Region of Southwest China - MDPI, accessed July 23, 2025,

View Source
Preview of Regenerative Agriculture—A Literature Review on the Practices and ..., accessed July 23, 2025,
Regenerative Agriculture—A Literature Review on the Practices and ..., accessed July 23, 2025,
Contextual Support Journal

Regenerative Agriculture—A Literature Review on the Practices and ..., accessed July 23, 2025,

View Source
Preview of Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,
Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 5, 2025,
Contextual Support Journal

Regenerative Agriculture—A Literature Review on the Practices and Mechanisms Used to Improve Soil Health - MDPI, accessed August 28, 2025,

View Source
Preview of Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon ... - Frontiers, accessed July 18, 2025
Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon ... - Frontiers, accessed July 18, 2025
Contextual Support Journal

The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil, accessed August 1, 2025

View Source
Preview of The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil, accessed on June 5, 2025
The biogeography of relative abundance of soil fungi versus bacteria in surface topsoil, accessed on June 5, 2025
Contextual Support Journal

Fungal to Bacterial Ratios: What and Why? - Ward Laboratories, Inc., accessed July 30, 2025,

View Source
Preview of The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 23, 2025,
The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 23, 2025,
Contextual Support Journal

The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 23, 2025,

View Source
Preview of The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 28, 2025
The Biogeography of Soil Bacteria in Australia Exhibits Greater Resistance to Climate Change Than Fungi - PubMed Central, accessed July 28, 2025
Contextual Support Journal

Responses of Soil Fungal Communities to Lime Application in Wheat Fields in the Pacific Northwest - Frontiers, accessed July 23, 2025,

View Source
Preview of Things you need to know about the Fungal to Bacterial Ratio (F:B) - MicroBiometer, accessed July 28, 2025
Things you need to know about the Fungal to Bacterial Ratio (F:B) - MicroBiometer, accessed July 28, 2025
Contextual Support GreyLiterature

Australian dryland soils are acidic and nutrient-depleted, and have unique microbial communities compared with other drylands - PMC, accessed July 23, 2025

View Source
Preview of What are the optimal fungal to bacterial biomass ratios for different crops? - ResearchGate, accessed July 28, 2025
What are the optimal fungal to bacterial biomass ratios for different crops? - ResearchGate, accessed July 28, 2025
Contextual Support GreyLiterature

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon ... - Frontiers, accessed July 21, 2025

View Source

Context

  • Region Australia
  • Biome Arid Karstic Woodlands & Shrublands
  • Land Use Agricultural Crop Production
  • Assessment Conservation Target
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 23 Mar 2026

Notes

The soil is not 'unhealthy'; rather, it has become a healthy soil for a different type of plant community.

Related Benchmarks

Other benchmarks in the AUS-AKW-AGR-SFB family.

— index Moderate
Agricultural Crop Production · Conservation Target
OptimalRange Active v1
0.3 index Moderate
Agricultural Crop Production · Conservation Target
LowerThreshold Active v1