Soil Nitrogen

AUS-AMR-AGR-SON General Moderate confidence

Benchmark Value

500 mg/kg

Direction: Higher is desirable ↑

Form: MinimumOnly

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 7 benchmarks together — the OptimalRange form drives the primary score, while 6 guard(s) constrain the result.

Contributing Benchmarks

OptimalRange Primary MinimumOnly Guard MinimumOnly Guard Point Guard MinimumOnly Guard MinimumOnly Guard OptimalRange Guard

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 (TN) concentration in topsoil (0-30 cm) layer.

Benchmark Definition:

Lower critical threshold below which soil nitrogen is insufficient to support ecosystem function in the Australian Arid Mountain Ranges & Uplands biome under agricultural crop production.

Justification:

Established from agronomic studies and typical mineral-to-total nitrogen relationships indicating critical deficiency below this level.

Sources (1)

Soil nitrogen—crop response calibration relationships and criteria for winter cereal crops grown in Australia - ResearchGate Journal

Soil nitrogen—crop response calibration relationships and criteria for winter cereal crops grown in Australia - ResearchGate

View Source

Supporting Sources (4)

Additional references from the underlying research that informed this benchmark.

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)

Contextual Support Government

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

View Source

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

View Source

Soil | Australia state of the environment 2021

Contextual Support GreyLiterature

Soil | Australia state of the environment 2021

View Source

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

View Source

Context

Region Australia
Biome Arid Mountain Ranges & Uplands
Land Use Agricultural Crop Production
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

Represents the floor for ecological function and sustainable cropping; below this level, the system is in a state of degradation ('N-mining'). AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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