Parameters for Site-Specific Soil Phosphorus Loss Modeling from Soil Test Data

his publication presents predictive equations for estimating the Langmuir (KL) and Freundlich (KF) phosphorus adsorption coefficients from routine soil-test measurements of phosphorus, iron, and aluminum used in Phosphorus Saturation Ratio (PSR) and Soil Phosphorus Storage Capacity (SPSC) calculations. The approach eliminates the need for time-consuming adsorption isotherm experiments and provides a rapid, cost-effective method for obtaining key soil phosphorus retention parameters. These estimates can be incorporated into nutrient transport models to improve site-specific assessment of phosphorus dynamics and phosphorus loss risk from manure- and fertilizer-impacted soils.