Full proceedings available at: http://www.extension.org/72793
The revision of the USDA-NRCS national standard for nutrient management in 2011 was driven, in part, by inconsistencies in state phosphorus (P) indices, rekindling debates over standardizing indices at regional or national scales. Reasonable arguments exist for maintaining the status quo, which allows for state specific site assessment approaches, as well as for regional and national P Indices, which would take advantage of expertise, resources and technologies that may not exist locally. In addition, a diversity of site assessment approaches have now been proposed that differ from the original P Index. Understanding the benefits and limitations provided with these approaches is key to advancing site assessment for P management.