Relating Field Indicators of Hydric Soils to Saturation and Reduction in Sandy Soils.
Gerren Lanier1, David Lindbo2, and Michael Vepraskas2. (1) Soil Science Dept North Carolina State Univ, Raleigh, NC 27695-7619, (2) Soil Science Dept, North Carolina State Univ, Raleigh, NC 27695-7619
Soil morphological features have been used to develop a list of field indicators that are used to identify hydric soils; these indicators were developed for both sandy soils as well as clayey and loamy soils. Formation of the sandy soil indicators in not completely understood because the durations of saturation and reduction needed to create these indicators is unknown. The objective of this study are to monitor water table fluctuation and oxidation-reduction (redox) potentials in sandy soils and relate these data to soil morphology, to compare the occurrence of saturation and reduction with soil color chromas and to determine which hydric soil indicator(s) best relate to wetland hydrology in sandy soils. An experimental study site was chosen on the Outer Banks on NC to monitor hydrology, redox potential, and soil morphological properties in fifteen soil plots along a hillslope containing members of the Fripp, Ousley, and Osier soil series. Results show that soils met the drainage class requirements for their soil series when colors with chromas of 3 or less were used to evaluate drainage class, also durations of saturation and reduction were sufficient to allow the development of the sandy redox (S5), thin dark surface (S9), and layer of muck (A9) field indicators at the base of the slope.