Fig. 4. Relationship between (a) water-extractable soil P and runoff filterable reactive phosphorus (FRP) from soil box and grassed and cropped field-plot studies of Aase et al. (2001), Andraski and Bundy (2003), Andraski et al. (2003), Daverede et al. (2003), Pote et al. (1996)(1999a, 1999b), Schroeder et al. (2004), and Torbert et al. (2002) where extraction coefficients did not differ significantly. Data from Pote et al. (1999a)(August experiments) are presented separately for clarity. Relationship between (b) soil P sorption saturation and dissolved P in runoff from soil box and grassed and cropped field plot studies of Andraski and Bundy (2003), Andraski et al. (2003), Kleinman and Sharpley (2003), Kleinman et al. (2002)(2004), Pote et al. (1996)(1999b), and Schroeder et al. (2004).