Soil Nitrogen — Benchmark Detail

Benchmark Value

500 mg/kg

Direction: Higher is desirable ↑

Form: MinimumOnly

Scoring Curve

Scoring curve unavailable

The scoring engine could not generate a curve for this benchmark context. The primary form is CompositeFramework, but the benchmark data may be missing required fields (e.g., optimal range bounds for an OptimalRange benchmark). This is typically a data quality issue in the benchmark pipeline.

Contributing Benchmarks

CompositeFramework Primary MaximumOnly Guard OptimalRange Guard MinimumOnly Guard MaximumOnly Guard Point Guard MinimumOnly Guard OptimalRange Guard MaximumOnly Guard Point Guard OptimalRange Guard Point Guard MinimumOnly Guard MaximumOnly Guard Point Guard MinimumOnly Guard MaximumOnly Guard OptimalRange Guard

Evidence & Context

Based on this, a lower critical threshold of approximately 500 mg/kg (0.05%) is proposed.

Metric Definition:

Lower critical threshold for Total Soil Nitrogen below which soil function is impaired

Benchmark Definition:

This benchmark defines the lower critical threshold of total soil nitrogen in the topsoil below which soil function is impaired in temperate semi-arid shrublands and open woodlands under production forestry.

Justification:

This value is substantially below the benchmark for a healthy native forest but above the most extreme levels of depletion observed in degraded landscapes.

Sources (1)

Preview of Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236.

Al-Beidh, S., & Al-Tawaha, A. R. M. (2023). Basic Properties and Mineralogy of Soils and Their Impact on the Growth of Jarrah Forest in Southwestern Australia. Land, 12(6), 1236. Journal

Soil Characteristics and Fertility of the Unique Jarrah Forest of Southwestern Australia, with Particular Consideration of Plant Nutrition and Land Rehabilitation - MDPI

View Source

Supporting Sources (1)

Additional references from the underlying research that informed this benchmark.

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

Context

Region Australia
Biome Temperate Semi-Arid Shrublands & Open Woodlands
Land Use Production Forestry
Assessment Not Stated
Evidence Type DegradationThreshold

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

Below this threshold, the soil's capacity to support resilient woodland functions is likely compromised. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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