In some North Carolina (NC) fields, historically excessive applications of animal wastes have resulted in net accumulations of soil Phosphorus (P) concentrations exceeding crop requirements. Phosphorus losses from such high P soils may threaten surface water quality in the form of eutrophication. The NC Phosphorus Loss Assessment Tool (PLAT) recognizes the use of riparian buffers as a best management practice to mitigate potential soil P losses through various pathways. Our objectives were (1) to validate that the list of NC Coastal Plain soils identified in PLAT as subject to leaching is accurate, (2) to assess the influence of riparian buffer soil type on attenuating P entrained from adjacent fields, and (3) to quantify the mitigation effects of riparian buffer practices on subsurface P loss transport under a range of diverse landscape, soil, hydrology, and other site-specific factors. Our findings will allow us to (1) update or revise the list of soils that PLAT identifies as likely to leach under high surface P conditions, (2) provide supportive data on the specific processes and factors controlling P losses via subsurface P transport from the field to a surface water, and (3) reduce farmer workload by identifying site specific conditions that will likely mitigate the transport of subsurface P from the field to a surface water source.