Soybean yields were measured for 3 years on 12 experimental plots established at each of the Holly Springs eroded sites.
The ESD's were approximately 74 cm for the uneroded [ILLUSTRATION FOR FIGURE 1A OMITTED], 60 cm for the slightly eroded [ILLUSTRATION FOR FIGURE 1B OMITTED], 42 cm for the moderately eroded [ILLUSTRATION FOR FIGURE 1C OMITTED], and 10 cm for the severely eroded [ILLUSTRATION FOR FIGURE 1D OMITTED].
The most striking morphological differences in this regard are the decrease in horizon thickness and the color change from very dark grayish brown (10YR 3/2) of the uneroded soil to yellowish brown (10YR 5/6) of the severely eroded soil, caused by the loss of organic matter and an increase in clay content (Table 1).
First, the amount of organic pigmentation decreases to the point where no pigment is visible in the moderately (ESD, 42 cm) and severely eroded (ESD, 10 cm) soils.
all severely eroded soils with Bt horizons (Alfisols and Argiudolls), except Tama, was greater than that in the associated slightly or moderately eroded soils (Table 4).
Eleven severely eroded pedons and eight moderately eroded pedons failed to meet one or more criteria for the taxonomic placement of the associated uneroded pedons (Table 5).
Seven of the nine severely eroded Mollisols failed to meet the color and or thickness criteria of a mollic epipedon.
Seven of the nine moderately eroded Mollisols did not classify in the same taxonomic placement as the associated slightly eroded or uneroded soil.