The Influence of Land-Use History on Soil Properties at Wormsloe Historic Site.

Wormsloe Historic Site, adjacent to Savannah, Georgia, contains nearly three centuries of post-colonial land use history, as well as evidence of Native American marine foraging.  Since colonial times, the 486 ha site included extensive areas cleared for cultivation and pasture agriculture as well as areas maintained in forest.  Following agriculture abandonment, most fields naturally regenerated to secondary forests. To evaluate how agriculture may still influence soil chemical and physical properties, 120 random sample points were established across two distinct land use areas: Agriculture (AGR) (agriculture activity from 1736 to present) and Reference (REF) (forest cover from 1736 to present); within two soil series mapped on the property (Chipley fine sand and Olustee fine sand); and within three distinct blocks according to geographic position (North, Central, South).  Field investigations revealed that, close to 100 years since abandonment, pH and P differed significantly across AGR and REF areas.  As well, significant differences were seen in nutrient values between soil series and among geographic positions.  Total C and N differed little across treatments (land use and soil series).  Evidence of an Ap horizon and potential reformation of a surface Bh were seen at many AGR points.  Additional areas of the property were selected for spatial investigations using geophysical instruments, Electromagnetic Induction and Electrical Resistance, which measured soil conductivity (mS m^-1) and apparent resistivity (ohm-meter), respectfully.  One 12 X 14 m grid with a 6 X 7 m nested grid, were each established at three pre-selected sites.  These instruments were useful for identifying evidence of human activity and artifacts not apparent from the surface.  Conductivity and apparent resistivity values contained greater variability within sites of high human activity than sites with minimal or no human activity.