Eolian Dust Erosion from an Agricultural Field on the North Carolina Coastal Plain

Abstract

Eolian erosion typically has not been considered a significant process on the humid southeastern coastal plain of the United States. A preliminary study of eolian erosion from an agricultural field was undertaken during the late winter of 2002 and early spring of 1999. During those times local agricultural practices leave fields bare while frontal systems produce frequent high wind events. Dust emissions were measured with two samplers; modified Wilson and Cooke passive dust traps and high-volume air samplers. Results of the study indicate that wind erosion is a significant process on agricultural fields of the North Carolina Coastal plain. Dust flux off of the field during the largest of five measured events was estimated as high as 126 kg/m with total losses of 3070 kg/ha. Atmospheric concentrations of suspended material were measured at 58,815 μgm^-3. Sediment erosion was not evenly distributed across the field. Erosion was focused over soils that are better drained. Low levels of soil moisture did not eliminate erosion but instead produced pulses of sediment emission as sustained wind continually dried then activated sequential layers of the field surface. Soil moisture and topography appear to be the primary controls on spatial erosion differences and soil characteristics likely play a secondary role.

Keywords:

• wind erosion
• aeolian erosion
• agricultural erosion
• dust