CHARACTERIZATION OF WIND EROSION SEDIMENTS IN THE RED RIVER VALLEY OF NORTH-DAKOTA

Wind erosion is a serious problem in the Red River Valley of North Dakota. Wind erosion sediments were characterized to evaluate their potential as nonpoint source pollutants for surface water and shallow groundwater. Thirty-four sites from the South Dakota border to the Canadian border were sampled to measure physical and chemical characteristics of displaced sediment and field soils. Collected sediments originated from fields with soils having silt loam, silty clay loam or silty clay textures. Sediments had >98% water-stable aggregates and average NO3--N levels of 105 mg kg-1. Calcareous sediments (22 samples) were significantly higher in pH, NO3--N and electrical conductivity (EC), while noncalcareous sediments (12 samples) were higher in P and K. Soils from sugar beet (Beta vulgaris L.) and small grain fields tended to have higher NO3--N levels than fields with other crops or cropping practices. Agricultural chemical residues were detected and identified at two sample sites. A comparison of displaced sediments with field soils showed significant increases in NO3--N, P, K and EC in the sediments and a significant reduction in pH. Nearly 96% of the NO3--N could be leached out of the sediments in an initial leaching. Wind erosion sediments have the potential to be nonpoint sources of NO3--N and salinity for surface and groundwater.