Inter-rill and rill erosion

Inter-rill and rill erosion move soil within the field boundary. Inter-rill erosion is defined as “soil movement that occurs when raindrops strike exposed soil.” The rain detaches the soil particles, splashes them into the air, and causes shallow overland flows. Raindrops striking these shallow flows (Figure 2) enhance the flows’ turbulence and help transport the detached sediment to nearby rill or concentrated flow areas. Rill erosion is defined as “erosion by concentrated flow in small rivulets.” (Figure 3 shows inter-rill and rill erosion. Figures 4a and 4b are Ohio examples.) Detached sediment might be deposited in a downslope area of the field or might remain suspended in concentrated flows that continue to develop gullies and exit the edge of the field, thus causing sediment deposition in ditches, streams, and rivers.
From an agronomic management standpoint, this type of erosion results in decreased productivity of the upslope area due to the movement of topsoil. This leaves the lower soil horizons exposed on the surface. Tillage might also be required to smooth the field surface before planting and/or passes of other Figure 2. Raindrop energy dislodges soil particles. Credit:
Figure 2. Raindrop energy dislodges soil particles.
Inter-rill and rill erosion
Figure 3. Inter-rill and rill erosion. Credit: USDA-NRCS.

Other Examples:

Inter-rill and rill erosionInter-rill and rill erosion
Figures 4a and 4b. Inter-rill and rill erosion resulting in residue and soil
movement in Ohio in spring 2017. Rill erosion through soybean residue, with
erosion continuing along the road (4a). Concentrated flow coming from right
to left, resulting in residue displacement and rill erosion (4b). Credit for both
images: Greg LaBarge, OSU Extension.

Best Management Practices