Soil pH

AUS-TSR-AGR-SPH General High confidence

Benchmark Value

7.5 pH
Thresholds: Lower: —, Upper: 7.5
Direction: Lower is desirable ↓
Form: UpperThreshold

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 10 benchmarks together — the OptimalRange form drives the primary score, while 9 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary OptimalRange Guard LowerThreshold Guard UpperThreshold Guard OptimalRange Guard OptimalRange Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard UpperThreshold Guard

Evidence & Context

An upper detrimental threshold is identified at pH(w) > 7.5, where micronutrient availability becomes limited.

Metric Definition:

Soil pH measured in water (pH(w)) indicating the acidity or alkalinity of soil affecting micronutrient availability.

Benchmark Definition:

Upper detrimental threshold for soil function where micronutrient availability is significantly reduced in tropical and subtropical rainforest agricultural soils.

Justification:

Above this level, micronutrient availability (e.g., iron, manganese, zinc) is significantly reduced, leading to deficiencies.

Sources (1)

Preview of Agriculture Victoria. (2024). Soil acidity.
Agriculture Victoria. (2024). Soil acidity.

Soil acidity | Soil | Farm management - Agriculture Victoria, accessed August 28, 2025

View Source

Supporting Sources (27)

Additional references from the underlying research that informed this benchmark.

Preview of 'Shannon Vale Station'- Weed control without herbicides - Soils For Life, accessed July 16, 2025,
'Shannon Vale Station'- Weed control without herbicides - Soils For Life, accessed July 16, 2025,
Contextual Support Journal

Case Study: Bananas - WetlandInfo, accessed July 16, 2025,

View Source
Preview of (PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,
(PDF) The pH of Australian soils: field results from a national survey - ResearchGate, accessed July 25, 2025,
Contextual Support Journal

Soil pH | Environment, land and water - Queensland Government, accessed August 28, 2025,

View Source
Preview of 6. LAND CAPABILITY CLASSES ON THE FORTH MAP, accessed July 16, 2025,
6. LAND CAPABILITY CLASSES ON THE FORTH MAP, accessed July 16, 2025,
Contextual Support Journal

The role of active fractions of soil organic matter in physical and chemical fertility of Ferrosols

View Source
Preview of A Benchmarking Approach to Assess Soil Health - SHI, accessed August 28, 2025,
A Benchmarking Approach to Assess Soil Health - SHI, accessed August 28, 2025,
Contextual Support GreyLiterature

Soil | Australia state of the environment 2021, accessed July 16, 2025,

View Source
Preview of ASC - VERTOSOLS - Soil Science Australia
ASC - VERTOSOLS - Soil Science Australia
Contextual Support

What are the optimum nutrient targets for pastures? - Soil Health Knowledgebase

View Source
Preview of Australian Journal of Soil Research, accessed July 16, 2025,
Australian Journal of Soil Research, accessed July 16, 2025,
Contextual Support

Australian Journal of Soil Research, accessed July 16, 2025,

View Source
Preview of Comparison of soil analytical methods for estimating plant-available potassium in highly weathered soils - CSIRO Publishing
Comparison of soil analytical methods for estimating plant-available potassium in highly weathered soils - CSIRO Publishing
Contextual Support Journal

Crop and Pasture Science - CSIRO PUBLISHING

View Source
Preview of Discover the Top 6 Benefits of Regenerative Farming in Australia, accessed July 16, 2025
Discover the Top 6 Benefits of Regenerative Farming in Australia, accessed July 16, 2025
Contextual Support Journal

Soil Health: Supporting Rural Industries in the Wet Tropics, accessed August 28, 2025,

View Source
Preview of Effects of agricultural management on soil carbon and pH in the Douglas Daly region of the Northern Territory - NT (Book), accessed on June 7, 2025
Effects of agricultural management on soil carbon and pH in the Douglas Daly region of the Northern Territory - NT (Book), accessed on June 7, 2025
Contextual Support Journal

General soil science principles and reviewed literature

View Source
Preview of Fertilising avocados | Business Queensland, accessed July 16, 2025,
Fertilising avocados | Business Queensland, accessed July 16, 2025,
Direct Evidence Government

Macadamia grower's guide 2022 - nutrition and soil health – part 1: the foundations - NSW Department of Primary Industries, accessed July 16, 2025,

View Source
Preview of Living soils in agriculture | TERN Australia, accessed July 25, 2025,
Living soils in agriculture | TERN Australia, accessed July 25, 2025,
Contextual Support Government

Living soils in agriculture | TERN Australia, accessed July 16, 2025,

View Source
Preview of Macadamia Grower guide has the answers - Australian Tree Crop Magazine, accessed July 16, 2025,
Macadamia Grower guide has the answers - Australian Tree Crop Magazine, accessed July 16, 2025,
Contextual Support Journal

Macadamia Grower guide has the answers - Australian Tree Crop Magazine, accessed July 16, 2025,

View Source
Preview of Macadamia grower's guide 2022 - nutrition and soil health – part 1: the foundations - NSW Department of Primary Industries
Macadamia grower's guide 2022 - nutrition and soil health – part 1: the foundations - NSW Department of Primary Industries
Contextual Support Journal

Macadamia Tree Yield Article by Australian Premium Macadamias, accessed July 16, 2025,

View Source
Preview of Managing Soils for Avocado Production and Root Health - Avocadosource.com, accessed July 16, 2025,
Managing Soils for Avocado Production and Root Health - Avocadosource.com, accessed July 16, 2025,
Contextual Support Journal

Considerations for developing and managing macadamia on floodplain soils - NSW Department of Primary Industries, accessed July 16, 2025,

View Source
Preview of Northern Rivers Soil Health Card - Perennial Horticulture
Northern Rivers Soil Health Card - Perennial Horticulture
Contextual Support Journal

Northern Rivers Soil Health Card - Perennial Horticulture, accessed July 16, 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 Health for Bananas | Terrain NRM, accessed July 16, 2025,
Soil Health for Bananas | Terrain NRM, accessed July 16, 2025,
Contextual Support Journal

Soil Health for Bananas | Terrain NRM, accessed July 16, 2025,

View Source
Preview of Soil Health Program | Boost Sugarcane Productivity, accessed July 18, 2025,
Soil Health Program | Boost Sugarcane Productivity, accessed July 18, 2025,
Contextual Support

National Soil Strategy, accessed July 16, 2025,

View Source
Preview of Soil pH | Environment, land and water - Queensland Government, accessed July 16, 2025,
Soil pH | Environment, land and water - Queensland Government, accessed July 16, 2025,
Contextual Support Journal

Northern Rivers Soil BMP Guide - Vegetables - SoilCare Incorporated, accessed July 16, 2025,

View Source
Preview of Soil pH: a key edaphic factor regulating distribution and functions of bacterial community along vertical soil profiles in red soil of pomelo orchard - PMC, accessed July 16, 2025,
Soil pH: a key edaphic factor regulating distribution and functions of bacterial community along vertical soil profiles in red soil of pomelo orchard - PMC, accessed July 16, 2025,
Contextual Support Journal

Soil pH: a key edaphic factor regulating distribution and functions of bacterial community along vertical soil profiles in red soil of pomelo orchard - PMC, accessed July 16, 2025,

View Source
Preview of The Importance of Soil pH for a Thriving Garden, accessed July 16, 2025,
The Importance of Soil pH for a Thriving Garden, accessed July 16, 2025,
Contextual Support Journal

Influence of changed management of sugarcane on some soil chemical properties in the humid wet tropics of north Queensland | Request PDF - ResearchGate, accessed July 16, 2025,

View Source
Preview of The legacy of intensive agricultural history on the soil health of (sub)tropical landscapes, accessed July 16, 2025,
The legacy of intensive agricultural history on the soil health of (sub)tropical landscapes, accessed July 16, 2025,
Contextual Support

The Influence of Soil pH on Microbial Community Structure and Function - UQ eSpace - The University of Queensland, accessed July 16, 2025,

View Source
Preview of Tropical agricultural land management influences on soil microbial communities through its effect on soil organic carbon | Request PDF - ResearchGate, accessed July 16, 2025,
Tropical agricultural land management influences on soil microbial communities through its effect on soil organic carbon | Request PDF - ResearchGate, accessed July 16, 2025,
Contextual Support GreyLiterature

(PDF) Banana root and soil health project - Australia - ResearchGate, accessed July 16, 2025,

View Source
Preview of TROPICAL SOILS | Terrain NRM, accessed July 16, 2025,
TROPICAL SOILS | Terrain NRM, accessed July 16, 2025,
Contextual Support Journal

Water Retention - Oz Soils 4 - UNE, accessed May 11, 2025,

View Source
Preview of Understanding soil pH - Queensland Government publications, accessed July 16, 2025,
Understanding soil pH - Queensland Government publications, accessed July 16, 2025,
Contextual Support Journal

Understanding soil pH - Queensland Government publications, accessed July 16, 2025,

View Source
Preview of Understanding soil pH, accessed July 16, 2025,
Understanding soil pH, accessed July 16, 2025,
Contextual Support Journal

SOIL ACIDITY - Incitec Pivot Fertilisers, accessed July 16, 2025,

View Source
Preview of Understanding soil tests for pastures | Soil | Farm management ..., accessed July 7, 2025,
Understanding soil tests for pastures | Soil | Farm management ..., accessed July 7, 2025,
Contextual Support Government

Soil Acidity | Fact Sheets | soilquality.org.au, accessed July 16, 2025,

View Source

Context

  • Region Australia
  • Biome Tropical & Subtropical Rainforests
  • Land Use Agricultural Crop Production
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 24 Mar 2026

Notes

This condition typically results from over-liming and indicates a detrimental state for soil health.

Related Benchmarks

Other benchmarks in the AUS-TSR-AGR-SPH family.

— pH High
Agricultural Crop Production · Pristine Reference
OptimalRange Active v2
5.5 pH High
Agricultural Crop Production · Pristine Reference
LowerThreshold Active v1
— pH High
Agricultural Crop Production · Pristine Reference
OptimalRange Superseded v1