Wednesday, November 7, 2007
325-7

Relating Field Indicators of Hydric Soils to Saturation and Reduction in Coarse Loamy Soils.

David Lindbo, PO Box 762, North Carolina State University, North Carolina State University, Soil Science Department, Raleigh, NC 27695-7619 and Erik Severson, USDA-NRCS, 3119 Rose Rdg, Clintwood, VA 24228-7746.

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 Loamy soil indicators related to durations of saturation and reduction needs to be documented. The objective of this study are to monitor water table fluctuation and oxidation-reduction (redox) potentials in loamy 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. An experimental study site was chosen on the lower Coastal Plain on NC to monitor hydrology, redox potential, and soil morphological properties in fifteen soil plots along a hillslope containing members of the Foreston, Stallings and Murville soil series. Preliminary data shows that soils met the drainage class requirements for their soil series when colors with chromas of 2 or less were used to evaluate drainage class, also durations of saturation and reduction were sufficient to allow the development of the Depleted Matrix (F3), Umbric surface (F13), and layer of muck (A9) field indicators at the base of the slope.