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.
Evidence & Context
For soils with Low to Moderate PBI (e.g., PBI approximately 70-280), which includes many loamy and some clayey Kandosols and Vertosols: 20-35 mg/kg.
soil phosphorus refers primarily to plant-available phosphorus fractions, with a focus on measurements obtained via the Colwell-P test (expressed in mg/kg)
This benchmark defines the target operational range of plant-available soil phosphorus (Colwell-P) for loamy and some clayey soils with low to moderate phosphorus buffering capacity under regenerative agricultural crop production in tropical monsoonal savannas.
This proposed range aims to balance crop productivity with ecological health. The lower bounds are informed by agronomic critical levels required for achieving approximately 90% of maximum relative yield for common crops.
Sources (1)
Soil phosphorus–crop response calibration relationships and criteria for winter cereal crops grown in Australia - CSIRO Publishing
View SourceSupporting Sources (3)
Additional references from the underlying research that informed this benchmark.
Based on levels indicating severe P deficiency for plant growth and likely impairment of soil ecological functions (e.g., microbial activity, nutrient cycling), drawing from S18, S43, S44, S50 (interpreted for cropping context).
Based on levels where P loss to the environment (leaching/runoff) becomes a significant risk, or where potential for P toxicity or nutrient imbalances may arise. Threshold is highly dependent on soil PBI, texture, and hydrology.
Derived synthesis from 1, S26, S41, S55, S56, S68, with ecological interpretation and adjustment for regenerative principles.