The National Soil Erosion Research Laboratory
The erosion prediction procedure from this project is to apply to "field-sized" areas or conservation treatment units. Although the size of a particular field to which the procedure applies will vary with degree of complexity within a field, the maximum size "field" is about a section (640 acres). However, the procedure will not apply to agricultural fields or watersheds having incised, permanent channels such as classical gullies and stream channels. The channels that the procedure is to include are those farmed over and known as concentrated flow or "cropland ephemeral gullies." Also, the procedure is to apply to constructed waterways like terrace channels and grassed waterways. In rangeland and forest applications, "fields" can include gullies up to the size of typical concentrated flow gullies in 640 acre cropland fields. These channels are on the order of about 3 to 6 ft in width by about 3 ft deep. The procedure is not expected to apply to headcut erosion, sloughing of gully sidewalls, or the effects of seepage on erosion in concentrated flow channels.