Genesis and Profile Development of Success Soils, Northern New Hampshire

Models of podzolization for northern New England soils are largely limited to organo‐chelate models, which are adequate to explain ortstein development but are inadequate to explain other types of indurated horizons, such as those observed in the Success series (sandy‐skeletal, mixed, frigid, ortstein Typic Haplorthod). In order to better understand the genesis of these soils, which have light‐colored, indurated horizons below ortstein horizons, oxalate‐extractable Si, Al, Fe, total C, pH, and micromorphological properties were determined for six pedons. Profile distributions of Si and Al and Fe and C were positively correlated ( r 2 > 0.90 and ≈0.7, respectively), but Fe and Al, Al and C, Si and Fe, and C and Si were not significantly related. Estimated allophane contents calculated from Si and Al were significantly higher in Bsm and BCm horizons than in Bhs and Bhsm horizons, as were pH values, while Bsm and BCm horizons had significantly less C and Fe than Bhs and Bhsm horizons. The Bsm horizons also had significantly lower pH values and higher estimated allophane values than BCm horizons. Allophanic grain cutans (allans) form intergrain bridges in BCm horizons, and grains in Bhsm and Bsm horizons have additional dark cutans abruptly adjacent to the allans. This suggests two separate phases of translocation, in which inorganic sesquioxide and allophanic sols are deposited during an initial phase that forms Bsm and BCm horizons, and organic compounds are illuviated in a subsequent phase, creating Bhs and Bhsm horizons.