PHYSICAL-PROPERTIES OF SELECTED SOILS BY EROSION CLASS

The effects of soil erosion on soil fertility and yield have been documented with data as early as the 1900s, but there is limited literature relating soil erosion and soil physical properties. A regional research project (NC-174) was established in 1984 to elucidate the effects of erosion on soil productivity, with respect to changes in soil physical properties, and to determine the potential for using computer models to simulate this effect. Data are presented from 15 soils (sites) located in eight states in the North Central United States. Based on the thickness of topsoil, two to three levels of prior erosion were identified at-each location. Soil samples were collected and analyzed for bulk density, water retention, particle size analysis, and hydraulic conductivity at saturation. Rooting depth for each soil was also determined from field observations. Soil erasion primarily affected the physical properties of the Ap horizon. Clay content of the Ap horizon increased with increasing erosion. In most cases, bulk density increased slightly and hydraulic conductivity of saturated sail decreased. Changes in water content at given tensions were mixed with increases in some cases and decreases in others with erosion.