Fig. 2. Relationship between Mehlich 3–extractable soil P and runoff filterable reactive phosphorus (FRP) for the grassed field-plot studies of (a) Pote et al. (1999a)(1999b; May experiments), Schroeder et al. (2004), and Torbert et al. (2002), and of (b) Pote et al. (1996)(1999a; August experiments).