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Agricultural best management practices (BMPs) can be used to improve the water quality of impaired watersheds where phosphorus (P) reduction is required by total maximum daily loads (TMDLs) regulation. Export of dairy manure through turfgrass sod may be a cost effective means to reduce nutrient loading on impaired watersheds. Previous plot-scale experiments indicated that 46 to 77% of the applied manure P was removed in a single sod harvest. New turfgrass research has been conducted at the field scale using composted dairy manure where two fields, 1.4 ha in size, have been instrumented to monitor surface runoff. One field received only inorganic fertilizer while the other field utilized composted dairy manure for turfgrass production. The surface runoff from each field was quantified and sampled for all runoff events to assess the transport of P to the surface water. Runoff and the mass of P in each field were compared and analyzed. Total dissolved P concentrations in the runoff were directly related to P concentrations in the soil. A total of 3.8% of the applied P from composted dairy manure was lost in the surface runoff.