Soil Phosphorus
Benchmark Value
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 2 benchmarks together — the MinimumOnly form drives the primary score, while 1 guard(s) constrain the result.
Contributing Benchmarks
Evidence & Context
A pivotal document from Meat & Livestock Australia (MLA), summarizing extensive research, states that it becomes "increasingly difficult on soils with a moderate phosphorus buffering index to retain native perennial grasses once phosphorus levels exceeded 20 Colwell P".
Available phosphorus (Colwell-P) levels in soil
This benchmark represents the ecological threshold for available phosphorus in soils with a moderate Phosphorus Buffering Index, beyond which native perennial grass diversity declines in grazed temperate semi-arid woodlands.
This value is specifically for soils with a moderate Phosphorus Buffering Index (PBI); exceeding this level is strongly correlated with the loss of native plant species richness and dominance of exotic annuals.
Sources (1)
Soil nutrient critical limits | MBFP | More Beef from Pastures - MLA
View SourceSupporting Sources (3)
Additional references from the underlying research that informed this benchmark.
Cycling of phosphorus in grazing systems - NSW Department of Primary Industries
View SourceCritical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials - CSIRO Publishing
View SourceIndicative Soil Phosphorus Report | LongPaddock | Queensland Government, accessed August 1, 2025
View Source