Fig. 1. a. Changes in porewater–floodwater phosphate and porewater Fe²⁺ concentrations for lower-P soils. Note the different scale for Fe(II) in Soil 4.

b. Changes in porewater–floodwater phosphate and porewater Fe²⁺ concentrations for Soils 6 and 8 (lower-P soils with a higher P release to floodwater than those in Fig. 1a)