Fig. 2. (a) Ferricyanide and (b) ferrocyanide sorption in soil horizons containing >10 g Corg kg-1 (#10 Ap; #11 Ah; #12 fluvic Ah; #13 Ah; #14 Ap; #15 fluvic Ah; #16 fluvic Bg; #17 mollic Ah). Isotherms are plotted following Eq. [1].