Soil Nitrogen

AUS-TDG-AGR-SON General Moderate confidence

Benchmark Value

No specific value — see range
Range: 750 to 1000 mg/kg
Thresholds: Lower: 750, Upper: 1000
Optimal Range: 750 to 1000
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. 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 Point Guard LowerThreshold Guard OptimalRange Guard UpperThreshold Guard OptimalRange Guard Point Guard LowerThreshold Guard OptimalRange Guard

Evidence & Context

A lower critical threshold for total soil nitrogen, below which ecological health and sustainable productivity are significantly compromised, is estimated to be in the range of 750–1000 mg/kg.

Metric Definition:

Total soil nitrogen concentration in the topsoil

Benchmark Definition:

This benchmark defines the lower critical threshold range of total soil nitrogen in the topsoil below which soil ecological health and sustainable agricultural productivity are significantly compromised in temperate Australian agricultural systems.

Justification:

This estimation is based on documented historical declines where native soil N levels have been halved due to prolonged conventional cropping.

Sources (1)

Preview of Strategic tillage of a long-term, no-till soil has little impact on soil characteristics or crop growth over five years
Strategic tillage of a long-term, no-till soil has little impact on soil characteristics or crop growth over five years Journal

What is Regenerative Agriculture? - Soils For Life, accessed August 13, 2025,

View Source

Supporting Sources (25)

Additional references from the underlying research that informed this benchmark.

Preview of (PDF) Soil and Landscape Grid of Australia - ResearchGate
(PDF) Soil and Landscape Grid of Australia - ResearchGate
Contextual Support

SLGA: Soil and Landscape Grid of Australia (Soil Attributes) | Earth Engine Data Catalog, accessed July 26, 2025,

View Source
Preview of $3.5M national project to examine ways to boost soil organic matter - CSIRO
$3.5M national project to examine ways to boost soil organic matter - CSIRO
Contextual Support Government

$3.5M national project to examine ways to boost soil organic matter - CSIRO, accessed August 28, 2025

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

Root Structure and Functioning for Efficient Acquisition of Phosphorus: Matching Morphological and Physiological Traits

View Source
Preview of Biological nitrogen fixation and prospects for ecological intensification in cereal-based cropping systems - PubMed Central
Biological nitrogen fixation and prospects for ecological intensification in cereal-based cropping systems - PubMed Central
Contextual Support Journal

Biological nitrogen fixation and prospects for ecological intensification in cereal-based cropping systems - PubMed Central

View Source
Preview of Categories - nitrogen - CSIRO Data Access Portal
Categories - nitrogen - CSIRO Data Access Portal
Contextual Support Government

Categories - nitrogen - CSIRO Data Access Portal, accessed July 18, 2025,

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Preview of Effects of fire frequency and mowing on a ... - CSIRO Publishing
Effects of fire frequency and mowing on a ... - CSIRO Publishing
Contextual Support Journal

Effects of fire frequency and mowing on a ... - CSIRO Publishing

View Source
Preview of Focus Group – Regenerative agriculture for soil health - EU CAP Network
Focus Group – Regenerative agriculture for soil health - EU CAP Network
Contextual Support Journal

Managing Grazing to Restore Soil Health, Ecosystem Function, and Ecosystem Services - Frontiers

View Source
Preview of Global Change Impacts on Australian Wheat Cropping: Studies on Hydrology, Fertiliser Management and Mixed Crop Rotations Howden - ResearchGate
Global Change Impacts on Australian Wheat Cropping: Studies on Hydrology, Fertiliser Management and Mixed Crop Rotations Howden - ResearchGate
Contextual Support

Global Change Impacts on Australian Wheat Cropping: Studies on Hydrology, Fertiliser Management and Mixed Crop Rotations Howden - ResearchGate

View Source
Preview of Long-term use of cover crops and no-till shift soil microbial community life strategies in agricultural soil - PubMed Central
Long-term use of cover crops and no-till shift soil microbial community life strategies in agricultural soil - PubMed Central
Contextual Support Journal

Microbial Communities Associated With Long-Term Tillage and Fertility Treatments in a Corn-Soybean Cropping System - PubMed Central

View Source
Preview of Long‐term (64 years) annual burning lessened soil organic carbon and nitrogen content in a humid subtropical grassland - EPub Bayreuth
Long‐term (64 years) annual burning lessened soil organic carbon and nitrogen content in a humid subtropical grassland - EPub Bayreuth
Contextual Support Journal

Long‐term (64 years) annual burning lessened soil organic carbon and nitrogen content in a humid subtropical grassland - EPub Bayreuth

View Source
Preview of Nitrogen balance in Australia and nitrogen use efficiency on Australian farms | Request PDF
Nitrogen balance in Australia and nitrogen use efficiency on Australian farms | Request PDF
Contextual Support Journal

Nitrogen balance in Australia and nitrogen use efficiency on Australian farms | Request PDF

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 Metrics: Soil chapter, accessed May 12, 2025
Regenerative Agriculture Metrics: Soil chapter, accessed May 12, 2025
Contextual Support Journal

WBCSD. Regenerative Agriculture: Soil Health Metrics.

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 Regenerative opportunities for building soil biological resilience – a case study in the low-rainfall zone in Southern Australia - CSIRO Research Publications Repository
Regenerative opportunities for building soil biological resilience – a case study in the low-rainfall zone in Southern Australia - CSIRO Research Publications Repository
Contextual Support GreyLiterature

Regenerative opportunities for building soil biological resilience – a case study in the low-rainfall zone in Southern Australia - CSIRO Research Publications Repository

View Source
Preview of Review of C:N Ratios in Vegetation, Litter and Soil Under Australian Native Forests and Plantations - DCCEEW
Review of C:N Ratios in Vegetation, Litter and Soil Under Australian Native Forests and Plantations - DCCEEW
Contextual Support Journal

Review of C:N Ratios in Vegetation, Litter and Soil ... - DCCEEW

View Source
Preview of Soil and Landscape Grid National Soil Attribute Maps - Total Nitrogen (3" resolution) - Release 2 - CSIRO Data Access Portal, accessed August 5, 2025,
Soil and Landscape Grid National Soil Attribute Maps - Total Nitrogen (3" resolution) - Release 2 - CSIRO Data Access Portal, accessed August 5, 2025,
Contextual Support Government

Geology | Norfolk Island National Park | Parks Australia, accessed August 2, 2025

View Source
Preview of Soil management in relation to sustainable agriculture and ...
Soil management in relation to sustainable agriculture and ...
Contextual Support Journal

Soil management in relation to sustainable agriculture and ...

View Source
Preview of Soil Research - CSIRO PUBLISHING
Soil Research - CSIRO PUBLISHING
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 13, 2025

View Source
Preview of Stubble and nutrient management to build soil carbon – challenges ...
Stubble and nutrient management to build soil carbon – challenges ...
Contextual Support Government

Stubble and nutrient management to build soil carbon – challenges and opportunities - Grains Research and Development Corporation (GRDC), accessed July 17, 2025

View Source
Preview of Sustainability of nutrient management in grain production systems of south-west Australia
Sustainability of nutrient management in grain production systems of south-west Australia
Contextual Support Journal

Sustainability of nutrient management in grain production systems of south-west Australia

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Preview of The Abundance of Microbial Functional Genes in Grassy Woodlands ..., accessed August 5, 2025,
The Abundance of Microbial Functional Genes in Grassy Woodlands ..., accessed August 5, 2025,
Contextual Support Journal

Grey Box (Eucalyptus microcarpa) Grassy Woodlands and Derived Native Grasslands of South-eastern Australia, accessed August 4, 2025,

View Source
Preview of The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N 2 O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols - CSIRO Publishing
The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N 2 O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols - CSIRO Publishing
Contextual Support Journal

The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N 2 O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols - CSIRO Publishing

View Source
Preview of The nitrogen book: Principles of soil nitrogen fertility management in southern Queensland and northern New South Wales farming
The nitrogen book: Principles of soil nitrogen fertility management in southern Queensland and northern New South Wales farming
Contextual Support Journal

Soil condition | NSW State of the Environment, accessed August 4, 2025,

View Source
Preview of www.fertilizer.org
www.fertilizer.org
Contextual Support

www.fertilizer.org

View Source

Context

  • Region Australia
  • Biome Temperate Dry Woodlands & Native Grasslands
  • Land Use Agricultural Crop Production
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Superseded
  • Version 2
  • Effective From 15 Mar 2026
  • Effective To 15 Mar 2026

Notes

Levels below this range likely indicate severe soil degradation, impaired biological function, reduced nutrient supply capacity, and compromised ecosystem resilience.

Related Benchmarks

Other benchmarks in the AUS-TDG-AGR-SON family.

— mg/kg Moderate
Agricultural Crop Production · Pristine Reference
OptimalRange Active v3
— mg/kg Moderate
Agricultural Crop Production · Pristine Reference
OptimalRange Superseded v2
— mg/kg Moderate
Agricultural Crop Production · Pristine Reference
OptimalRange Superseded v1
— mg/kg Moderate
Agricultural Crop Production · Pristine Reference
OptimalRange Superseded v1