Data presentation, interpretation, and communication

Abstract

The oxidation‐reduction state of Fe in some pure clays affects the extractability of K, but the magnitude of the effect in whole soils is largely unexplored. Samples of a Hoytville soil (fine, illitic, mesic Mollic Epiaqualf ), taken from undrained and artificially drained sites in Ohio, were amended with 0, 50, or 100 mg K kg^‐1, and either moistened with 140 g kg^‐1 water or flooded for incubation. After each of two sequential incubation periods, samples were taken from wet soils and immediately air‐dried, and were also taken from soils air‐dried over 11–13 days. Samples were analyzed for Fe (II), ammonium‐acetate‐extractable K, and Mehlich‐3‐extractable K. Neither extractant reliably detected increases in extractable K due to K additions. The Mehlich 3 extractant removed more K from samples than did ammonium acetate. Small but inconsistent, changes in Fe (II) concentration due to treatment were noted. Differences in extractable K concentrations between samples were not generally related to differences in Fe (II) concentrations.