Gully erosion control is an important issue on rural, suburban, and urban land
Gullies can have serious negative impacts including loss of cropland, loss of access to a portion of land, and reduced water quality downstream from the affected area.
Why do gullies form?
Gullies can form because of a combination of topography, land use, climate, weather events, and soil properties. Gullies are usually triggered because of a change in land use practices and are exacerbated by intense storms. When runoff exceeds infiltration, soil erosion by water begins. Any activity that disturbs soil structure can contribute to erosion. Ironically, whether soil structure is loosened with tillage or compacted by traffic, water movement into the soil can be negatively impacted. Gullies form when water concentrates into a flow path.
Practices such as tillage in crop production, subdivision development, road construction, and over grazing have the potential to negatively alter soil structure, making gully formation an issue for both rural, suburban, and urban landowners. Many recent questions on gully formation received by Extension specialists have come from small property owners.
Two types of gullies
Classical gullies are concentrated flow erosion features that are too large or deep for normal farming implements to cross.
Ephemeral gullies are small channels of eroded soil that form in unprotected soils (such as cropland and construction sites) during extreme storm events. These gullies are shallow enough they can be removed by tillage.
Figure 2 Ephemeral gully. Photo by Aleksey Sheshukov, K-State Research and Extension.
How can gullies be controlled?
Treatment of classical gully erosion is costly. It is worthwhile to do so, however, because if it is not controlled, the gully will continue to become larger and damage more land area. The land must be filled and graded, permanent vegetation such as trees or grasses would need to be established, and permanent control structures would have to be designed and installed (see section below on where to go for help).
Treatment and prevention of ephemeral gullies is best accomplished with a two-fold approach. First, practices that increase infiltration across the whole field or site are very important, and that involves rebuilding soil structure. This can be done with no-till farming practices or by rapidly establishing vegetation, such as planting temporary cover such as spring oats. The second aspect is to establish permanent structures on the ephemeral gully itself, such as a grassed waterway, terraces, diversions, or possibly a sediment basin or pond. In a field with active gullies, it is imperative to use both soil-structure building practices and structures that control runoff, otherwise the problem will come back with the next intense rainstorm event.
Where to go for help
If you have either type of gullies, immediate action should be taken to control them before they get any bigger. The best place to begin is your local USDA-Natural Resources Conservation Service office, which you can locate on the Contact Us page at http://www.nrcs.usda.gov/ Each and every situation is different, and the NRCS staff are able to provide technical expertise on the strategies that would best address your particular site.
USDA, 2007 publication, Gullies and Their Control: http://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17826.wba
K-State Research and Extension publication MF-1064, Maintaining Grassed Waterways: http://www.bookstore.ksre.ksu.edu/pubs/MF1064.pdf
K-State Research and Extension publication C-709, Terrace Maintenance: https://www.bookstore.ksre.ksu.edu/pubs/C709.pdf
DeAnn Presley, Soil Management Specialist
Aleksey Sheshukov, Water Quality Specialist, Biological and Agricultural Engineering