Understanding and Interpreting Oxyaquic Conditions.

Hydropedologic studies related to seasonal saturation and hydraulic conductivity add to our knowledge to make accurate land use interpretations, particularly as related to land application of waste (liquid and solids) and many urban land uses.  Soils mapped in the Carolina Slate Belt in the southeastern region of the United States, including the benchmark Tatum and Chewacla Series, are no exception to this and proper identification of seasonal saturation in these soils is critical as urban and suburban development increases in this region.   Soils related to the Catena may lack the typical 2 chroma redox depletions commonly used to identify seasonal saturation even though high water table is often directly observed in these soils.  When a seasonal high water table is determined, the soil may be classified as oxyaquic.  However, if 2 chroma depletions are absent (or present at deeper depths than seasonal saturation) local or state land use codes may misidentify the depth to saturation.  Therefore, even when a soil is classified as oxyaquic, local and state codes do not always interpret this as a limitation for waste treatment and dispersal purposes.  The result is that soils in this region’s toposequence (particularly Georgeville-Tatum-Lignum-Chewacla) may be inappropriately used for waste disposal and other purposes.  Along with proper identification of saturation, soil hydraulic conductivity measurements are needed.  The soils listed above all have similar hydraulic conductivities listed in their current interpretations, yet anecdotal field data from consultants indicate a wide range in measured values.  Possible reasons for the wide range in hydraulic conductivity values have not been well researched.  This proposal specifically seeks to provide information for improved interpretations of soil and land use for this toposequence that include the benchmark series listed above.  The toposequence will be investigated following a hydropedologic approach, including water table and hydraulic conductivity assessments.  The data attained can then be used to improve urban land use interpretations (e.g., septic systems, land application for waste treatment, storm water BMP design).  In addition to the above benefits of this project data will also provide supporting data for the initial soil survey in Caswell County, North Carolina and provide basis for MLRA Soil Survey projects in the Carolina Slate Belt, including completion of the extensive revision of Alamance County, North Carolina.