Submitted to: Joint Federal Interagency Sedimentation and Hydrologic Modeling
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2010
Publication Date: June 29, 2010
Citation: Wells, R.R., Bingner, R.L., Wilson, G.V., Hanson, G.J. 2010. Soil erodibility evaluation under different management practices [abstract]. Proceedings of the Joint Federal Interagency Sedimentation and Hydrologic Modeling Conference, June 27 - July 1, 2010, Las Vegas, Nevada. CD-ROM. Technical Abstract: Soil erosion is a major factor leading to water quality degradation throughout the United States. Soil erosion involves particle detachment and transport, followed by deposition. The ability of water to detach and transport soil particles is known as the soil’s erodibility. Soil erosion is a result of several factors, including soil properties, rainfall intensity, slope steepness, slope length, vegetative cover, and management practice. Although the factors are well known, soil erosion in ephemeral gullies is not well understood. When assessing soil erosion and ephemeral gully development in fields, it is important to account for the soil properties as well as the soil's erosion potential, since the erosion potential is linked to antecedent soil properties. The soil's erosion potential/erodibility is impacted by several factors, including the amount of organic matter in the soil, the texture of the soil, the antecedent water content, and the permeability of the surface horizon. Several tests have been developed over the years to measure erodibility of earthen materials, particularly for dams and embankments; here we discuss measurements taken using an impinging jet apparatus on farm fields under different management practices. Water is discharged through a 0.01 mm nozzle at pressures ranging from 10 to 22 kPa onto field soils under till and no-till management in Kansas and Mississippi in and near ephemeral gullies. Field data include water quality of the eroding fluid, scour depth measurement with time, soil water content, and soil texture. Several observations were made: (1) limited variability in water quality parameters produced nothing substantial, (2) impinging jets offer a good measurement of the in-situ soil erodibility, (3) distinct differences in soil erodibility arise in till and no-till managed fields, and (4) soil properties must be taken into account when determining soil erodibility.