TY - JOUR T1 - Comparing ratings of the southern phosphorus indices JF - Journal of Soil and Water Conservation SP - 325 LP - 337 VL - 61 IS - 6 AU - D.L. Osmond AU - M.L. Cabrera AU - S.E. Feagley AU - G.E. Hardee AU - C.C. Mitchell AU - P.A. Moore, Jr. AU - R.S. Mylavarapu AU - J.L. Oldham AU - J.C. Stevens AU - W.O. Thom AU - F. Walker AU - H. Zhang Y1 - 2006/11/01 UR - http://www.jswconline.org/content/61/6/325.abstract N2 - The use of site assessment indices to guide agricultural phosphorus (P) nutrient management has been widely adopted in the United States. This study compares P-index ratings from 12 southern states (Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, South Carolina, Tennessee, and Texas) on fields representing three dominant southern agricultural systems: upland pasture, upland cornfield, and artificially drained field. The structure of each P-index varied enough to produce widely divergent ratings when applied to similar scenarios where individual factors (such as soil test P, poultry broiler litter application rate, or buffer absence or presence) were adjusted across a broad range of P-index input values. Variation in P-index ratings was the unique combination of each state's selected factors, weighting of the factors, and factor combination (added, multiplied, or a mixture of both addition and multiplication). Although the flexibility of and differences among the southern states' P-indices result in dramatically diverse P-index ratings for the same set of conditions, the diversity in P-index construction allows for indices designed to match individual state conditions and concerns. The substantial differences in P-index results identified in this survey highlight the need for close coordination between states in revising P-indices if they are to be applied across state lines. ER -