Soil Nitrogen

AUS-AMR-AGR-SON General Moderate confidence

Benchmark Value

500 mg/kg
Thresholds: Lower: 500, Upper: —
Direction: Higher is desirable ↑
Form: LowerThreshold

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.

Evidence & Context

Based on typical relationships between mineral and total N, a total N level below 500 mg/kg in the topsoil is considered critically low for sustainable cropping in this biome.

Metric Definition:

Total soil nitrogen level in the topsoil below which ecosystem function is compromised and degradation occurs.

Benchmark Definition:

Critical lower threshold for total soil nitrogen in mg/kg below which sustainable cropping is compromised in this biome.

Justification:

This threshold is based on agronomic studies and typical relationships between mineral and total nitrogen indicating degradation below this level.

Sources (1)

Preview of Critical concentrations for nitrogen, phosphorus, potassium and sulphur soil tests for break crops - Grains Research and Development Corporation (GRDC)
Critical concentrations for nitrogen, phosphorus, potassium and sulphur soil tests for break crops - Grains Research and Development Corporation (GRDC) Government

Critical concentrations for nitrogen, phosphorus, potassium and sulphur soil tests for break crops - Grains Research and Development Corporation (GRDC)

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Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Preview of Nitrogen supply and demand in Australian agriculture - ResearchGate, accessed July 25, 2025,
Nitrogen supply and demand in Australian agriculture - ResearchGate, accessed July 25, 2025,
Contextual Support Journal

Regenerative agriculture — the practices involved and its position within modern agricultural systems

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Preview of Soil | Australia state of the environment 2021
Soil | Australia state of the environment 2021
Contextual Support GreyLiterature

Soil | Australia state of the environment 2021

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Preview of Soil and Landscape Grid of Australia; Soil nitrogen availability in the cereal zone of South Australia. I. Soil organic carbon, total nitrogen, and nitrogen mineralisation rates
Soil and Landscape Grid of Australia; Soil nitrogen availability in the cereal zone of South Australia. I. Soil organic carbon, total nitrogen, and nitrogen mineralisation rates
Direct Evidence Government

Soil and Landscape Grid National Soil Attribute Maps - Total Nitrogen (3" resolution) - Release 2

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Context

  • Region Australia
  • Biome Arid Mountain Ranges & Uplands
  • Land Use Agricultural Crop Production
  • Assessment Pristine Reference
  • Evidence Type DegradationThreshold

Lifecycle

  • Status Active
  • Version 1
  • Effective From 25 Mar 2026

Notes

Represents a state of degradation ('N-mining') characterized by chronic nitrogen deficiency symptoms and high dependence on external inputs.