Soil phosphorus (P) build-up from long-term application of poultry litter may increase P loss in surface and subsurface water and lead to eutrophication.  Pasture sites in North Louisiana were surveyed for elevation and grid sampled on 60 x 60, 30 x 30 and 15 x 15 m scales.  The soils included Darley (fine, kaolinitic, thermic Typic Hapludult) and Ruston (fine-loamy, siliceous, thermic Typic Paleudult) series.  Core samples of surface 0 – 5 cm, 5 cm – Bt and the first 5 cm of Bt were analyzed for P content, pH, organic C, oxalate-extractable Al and Fe, and texture.  Phosphorus sorption isotherms were also generated, fit to the Langmuir isotherm, and the data were geostatistically analyzed.  Isotherm parameters were spatially correlated and well-described by exponential and Gaussian semivariograms.  Among soil properties, P sorption parameters were best correlated with oxalate-extractable Al and Fe.   This study was part of a larger project where the goal is to refine a set of criteria that will allow an applicator to determine the amount of P that a specific location in a particular soil can retain without appreciable loss to surface waters.