A comparison of methods to determine total, organic, and available phosphorus in forest soils

Abstract
Several methods for the determination of soil phosphorus (P) in acidic forest soils were examined. The Parkinson and Allen digestion method removed more total P than did the ignition method, especially with mineral soils. There were problems with both the Saunders and Williams ignition method and the Bowman and Moir extraction protocol for organic P determination. The problems were more pronounced when used on organic soil samples The Bray P1 was better than the Mehlich 3 method for measuring available P in mineral soils.