Soil Nitrogen

AUS-TMS-AGR-SON General Moderate confidence

Benchmark Value

960 mg/kg

Direction: Higher is desirable ↑

Form: Point

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

The proposed benchmark for total soil nitrogen, representing a high level of environmental health under such management, is 960 mg/kg in the 0-10 cm soil layer.

Metric Definition:

Total soil nitrogen concentration in the topsoil (0-10 cm) of agricultural crop production systems.

Benchmark Definition:

This benchmark represents a high level of total soil nitrogen concentration in the topsoil of agricultural crop production systems in Tropical Monsoonal Savannas, indicating good environmental health achievable under regenerative management.

Justification:

Derived from a long-term study at Warra, Queensland, demonstrating nitrogen accretion via legume integration in a cropping system; principles applicable to Tropical Monsoonal Savannas.

Sources (1)

Preview of Comparison of legume-based cropping systems at Warra, Queensland. I. Soil nitrogen and organic carbon accretion and potentially mineralisable nitrogen.

Comparison of legume-based cropping systems at Warra, Queensland. I. Soil nitrogen and organic carbon accretion and potentially mineralisable nitrogen.

Comparison of legume-based cropping systems at Warra, Queensland. I. Soil nitrogen and organic carbon accretion and potentially mineralisable nitrogen.

View Source

Supporting Sources (5)

Additional references from the underlying research that informed this benchmark.

$Preview of Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty - BG, accessed August 5, 2025,$

Mapping soil organic carbon fractions for Australia, their stocks, and uncertainty - BG, accessed August 5, 2025,

Contextual Support Journal

Effect of fire and tree‐grass patches on soil nitrogen in Australian tropical savannas

View Source

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

Soil Nitrogen Supply | Fact Sheets | soilquality.org.au, accessed July 25, 2025,

Contextual Support Government

Nitrogen Fixation in Acacias - AgEcon Search, accessed July 30, 2025,

View Source

Soil organic carbon and total nitrogen under Leucaena ..., accessed May 11, 2025,

Contextual Support Journal

Soil organic carbon and total nitrogen under Leucaena ..., accessed May 11, 2025,

View Source

Soil organic carbon and total nitrogen under Leucaena leucocephala pastures in Queensland - ResearchGate

Contextual Support Journal

Soil organic carbon and total nitrogen under Leucaena leucocephala pastures in Queensland

View Source

Context

Region Australia
Biome Tropical Monsoonal Savannas
Land Use Agricultural Crop Production
Assessment Not Stated
Evidence Type ReferenceCondition

Lifecycle

Status Active
Version 1
Effective From 10 Jun 2026

Notes

No upper detrimental threshold — higher values are always better up to natural saturation. While the site is subtropical, the nitrogen accretion principles via legume leys are relevant to tropical monsoonal savannas. The benchmark represents a high environmental health state achievable under regenerative practices. AssessmentContext defaulted to 'Not Stated' because the source document did not state one.

Related Benchmarks

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