Phosphorus Buffering Index (PBI)
The Phosphorus Buffering Index (PBI) approximates the soil’s ability to ‘fix’ phosphorus (P). Soils with a high PBI quickly and tightly lockup P fertiliser making it unavailable to plants. Low PBI soils can’t bind the P, leaving most applied P for plant uptake. Consultants and Growers should use PBI to improve interpretation of critical Colwell