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ARS Home » Plains Area » Fort Collins, Colorado » Center for Agricultural Resources Research » Soil Management and Sugarbeet Research » Research » Publications at this Location » Publication #408155
Research Project: Agricultural Management for Long-Term Sustainability and Soil Health

Location: Soil Management and Sugarbeet Research

Title: A short history of the phosphorus index and Andrew Sharpley’s contributions from inception through development and implementation

Author
item OSMOND, DEANNA - North Carolina State University
item Kleinman, Peter
item COALE, F - University Of Maryland
item NELSON, NATHAN - Kansas State University
item Bolster, Carl
item MCGRATH, JOSHUA - Ocp Group

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/8/2023
Publication Date: 12/21/2023
Citation: Osmond, D., Kleinman, P.J., Coale, F., Nelson, N., Bolster, C.H., McGrath, J. 2023. A short history of the phosphorus index and Andrew Sharpley’s contributions from inception through development and implementation. Journal of Environmental Quality. https://doi.org/10.1002/jeq2.20535.
DOI: https://doi.org/10.1002/jeq2.20535

Interpretive Summary: The Phosphorus Index has been developed in nearly all states in America, offering flexibility in managing agricultural phosphorus to meet environmental and production needs. A product of a unique partnership between USDA, universities and other stakeholders, the Phosphorus Index has undergone an evolution that reflects coordinated science and a reaction to its performance. This assessment of the history of the Phosphorus Index includes a close examination of the role of Dr. Andrew Sharpley, a former USDA-ARS scientist, in developing scientific consensus behind this important decision support tool.

Technical Abstract: In the 1980s, growing recognition of agricultural phosphorus (P) sources to surface water eutrophication led to scrutiny of animal feeding operations. In 1990, the USDA-Natural Resources Conservation Service (NRCS) invited prominent scientists to find a solution. It was at an initial meeting that Dr. Andrew Sharpley suggested that P assessment could be modeled after the Universal Soil Loss Equation, where a matrix of factors would be associated with management recommendations. After codifying the P assessment into the USDA-NRCS 590 Nutrient Management Standard some 10 years later, 48 states chose to develop their own P Indices. Sharpley, working with many others, helped develop several different state P-Indices, as well as the multiplicative concept. In 2000, Sharpley secured funding from the USDA-Agricultural Research Service to support the National P Research Project, which conducted in-field runoff P assessment using standardized rainfall simulated studies across 20 states; this allowed individual trials to be aggregated for agroecological regions that were then incorporated into state P Indices. Eventually, comparison of P Indices across state boundaries led to a white paper at the behest of USDA-NRCS that resulted in three regional projects evaluating modeling approaches to support or replace P Indices. Sharpley's national umbrella project pointed to shortcomings in water quality models, such as APEX or TBET, as a replacement of state P-Indices, which remain a key part of the USDA-590 standard. As a selfless leader, capable of attracting and assembling diverse, interdisciplinary teams, Sharpley was essential to the inception, development, and implementation of the P Index.