The objective of this review paper is to evaluate methods of identifyi
ng eroded phases of a soil and quantifying the amount of soil from ero
sion. The effect of accelerated erosion on soils is recorded on Nation
al Cooperative Soil Survey maps as phases of soil series and reflect t
he percentage of the original A horizon remaining. This definition req
uires a knowledge of original A horizon thickness prior to cultivation
. Erosion classes based on erosion of topsoil underestimate the extent
of erosion from both the topsoil and subsoils, particularly where soi
ls have been cultivated for hundreds of years and are severely eroded.
For some soils, a major soil classification problem occurs when accel
erated erosion affects the diagnostic horizons.