Soil Nitrogen — Benchmark Detail

Benchmark Value

400 mg/kg

Thresholds: Lower: 400, 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 3 benchmarks together — the Point form drives the primary score, while 2 guard(s) constrain the result.

Contributing Benchmarks

Point Primary LowerThreshold Guard UpperThreshold Guard

Evidence & Context

For the reference loamy sand soil (76% sand), a drop to a level below 400 mg/kg could be considered a critical point.

Metric Definition:

Critical lower threshold of total soil nitrogen concentration indicating nutrient depletion

Benchmark Definition:

Lower critical threshold below which soil nitrogen depletion impairs ecosystem function

Justification:

Represents significant depletion of natural nitrogen capital below the reference state, risking long-term productivity loss.

Sources (2)

Preview of EFFECTS OF INTENSIFIED HARVESTING ON RATES OF NITROGEN AND PHOSPHORUS REMOVAL FROM PINUS RADIATA AND EUCALYPTUS FORESTS IN AUSTR - Scion Research

EFFECTS OF INTENSIFIED HARVESTING ON RATES OF NITROGEN AND PHOSPHORUS REMOVAL FROM PINUS RADIATA AND EUCALYPTUS FORESTS IN AUSTR - Scion Research Journal

EFFECTS OF INTENSIFIED HARVESTING ON RATES OF NITROGEN AND PHOSPHORUS REMOVAL FROM PINUS RADIATA AND EUCALYPTUS FORESTS IN AUSTR - Scion Research

View Source

Soil management guides - NSW Department of Primary Industries Journal

Soil management guides - NSW Department of Primary Industries

View Source

Supporting Sources (3)

Additional references from the underlying research that informed this benchmark.

Chapter 9 AUSTRALIAN GRASSLANDS - Food and Agriculture Organization of the United Nations, accessed August 5, 2025,

Contextual Support Government

Karst and agriculture in Australia - Digital Commons @ USF, accessed July 26, 2025,

View Source

Elevated carbon dioxide increases soil nitrogen and phosphorus availability in a phosphorus-limited Eucalyptus woodland

Direct Evidence Journal

Elevated carbon dioxide increases soil nitrogen and phosphorus availability in a phosphorus-limited Eucalyptus woodland

View Source

Temperate Grasslands - Greening Australia, accessed August 4, 2025

Contextual Support Journal

Managing natural areas | City of Gold Coast, accessed May 19, 2025

View Source

Context

Region Australia
Biome Temperate Grassy Woodlands & Plains
Land Use Production Forestry
Assessment Pristine Reference
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 24 Mar 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. Expert estimate based on nutrient removal from harvesting and soil organic matter maintenance.

Related Benchmarks

Other benchmarks in the AUS-TGP-FOR-SON family.