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 loamy to clayey soils with Moderate to High PBI (e.g., PBI >140): ... Values consistently > 50-70 mg/kg likely represent an unnecessary accumulation that increases long-term environmental risk
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 represents the upper detrimental threshold of plant-available soil phosphorus (Colwell-P) above which long-term environmental risks increase due to accumulation in loamy to clayey soils with high phosphorus buffering capacity under agricultural crop production in tropical monsoonal savannas.
Excessive accumulation still poses a risk of P loss via surface runoff and can lead to long-term soil P saturation.
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.