P is the support practice factor. Status, questions, answers, and the future'', describes the revision. For the eastern United States, R values are generally the same as those used in the USLE but includes some revisions. Values for farming across the slope are based on slope length and steepness, row grade, ridge height, storm severity, soil infiltration, and the cover and roughness conditions. The stripcropping P factor is based on the amount and location of soil deposition.
E is the estimation of average annual soil loss in tons per acre.
I is the soil erodibility index. K is the ridge roughness factor. C is the climatic factor. All climatic factor values are expressed as a percentage of the value established at Garden City, Kansas. Garden City, Kansas was the location of early research in the WEQ and established the standard for climatic factors against which the other locations are measured.