This product consists of two tabular datasets and associated metadata for major phosphorus fluxes including manure and fertilizer inputs, crop uptake, as well as waste water treatment facility effluent and river export. These are time series data representing water years 1992 to 2012 for watersheds associated with the National Water Quality Program Surface Water Trends project. Dataset 1: Major fluxes and estimated net P balances. Dataset 2: Results of a t-test to determine if site level mean agricultural P balances were significantly above, not different, or below zero. Each site was then assigned to an Accumulation, Equilibrium, or Depletion status categories, respectively. Identification of sites where river loads are impacted by legacy P. Estimated changes river export between 1992 - 2012.