Soil Formation

Soils that exist at the Weber Farm Site today began forming at the end of the Ice Age, about 13,000 years ago.  They formed in loess-derived silty parent material and sandy material derived from the underlying weathered sandstone bedrock.  Climatic conditions and native vegetation, when considered as soil-forming factors, are essentially constant across the site except as a function of slope steepness and slope aspect.  South and west facing portions of the study area receive somewhat more direct sunlight and north-facing portions of the study area receive somewhat less direct sunlight.  The affect of this difference was not addressed in this study.  However, it is likely that soils on south and west facing slopes in the study area exhibit higher soil temperatures, a longer frost-free season, and reduced soil moisture during the growing season, and soils on north facing slopes in the study area exhibit lower soil temperatures, a shorter frost-free season, and increased soil moisture during the growing season.  

Land use of the entire study area is cultivated row crops and forage crops.  Although cultivation practices have changed over time, the study area has been in more-or-less continuous production since it was originally homesteaded and first plowed, probably sometime during the 1860s.  Several lines of evidence suggest the severe soil erosion characteristic of much of the study area occurred recently, perhaps since the introduction of Euro American agricultural practices.  The presence of strongly developed Bt-horizons at depth in some upland settings indicate a substantial period of landscape stability, and soil formation, occurred during post-glacial time.  The weakly expressed horizonation above these horizons, and across the entire study area suggests this extended period of landscape stability and soil formation has only recently been interrupted.   

Land Use Recommendations

The most significant consideration with regard to land use in the study area is slope.  The sandy and silty texture soils in the study area are extremely susceptible to wind and water erosion when the stabilizing protection of vegetation cover is removed .  This is especially true in steeply sloping portions of the study area.  Soils on upland and adjacent steeply sloping portions of the study area already exhibit characteristics that are the direct result of soil erosion.  They are thin and sandy (due to the incorporation of sandy material derived from sandstone bedrock below them).   Much of the rich, fertile loess-derived parent material has been removed from this portion of the study area.  Soils in lower positions in the study area are thickened suggesting material eroded off adjacent uplands is, at least in part, being stored lower on the landscape.  In at least one case, redeposition of silty and sandy material eroded from upslope was rapid enough to bury a preexisting soil.  

We recommend that future land use of the study area mitigate for soil erosion.  Soils in the study area, though already affected by soil erosion, remain moderately fertile and suitable for cultivation.  Though thin, they can support some construction and can be used for a variety of earthen fill.  However, great care during any land use activity that removes or inhibits the establishment of vegetation should be taken.   Soil erosion control practices such as zero-tillage and contour plowing should be implemented if cultivation is to continue (at least sustainably).  Silt fences and soil berms should be in place during any construction.  Room for vegetated buffer strips should be left if the study area is to be used as a building site.  Soils at the site are best suited to "low impact" activities such as pasture or recreation areas.  Even if used for these purposes, care must be taken to control foot, animal, and vehicle traffic, especially on the steeper portions of the study area.  Any such activity that removes stabilizing vegetation will result in soil erosion.  Both soil erosion by wind (blowing and deflation) and soil erosion by water (sheetwash and gullying) is to be expected if the protection of stabilizing vegetation is removed and these soils are exposed.     

Specific land use recommendations are provided at the following links:

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