Knowledge Bank

Scioto Marsh in Hardin County, OH, was a 16,000-acre wetland area that was drained in the mid-1800s by channelizing the Scioto River to create farmland. The resulting soils are characterized by a thick, organic-rich A horizon that contributed to the productivity of the area. During the subsequent years, wind erosion and farming practices depleted this layer, causing the underlying B horizon to become incorporated into the till zone in many areas. This paper is a re-evaluation of the status of the A horizon, in lieu of recommendations thirty years ago on how to preserve the remaining productivity. Our study re-sampled sites from previous studies from the 1930s and 1970s. Comparisons of A-horizon thickness, organic carbon content, and bulk density indicate that the A horizon depletion has greatly diminished from its earlier pace. This is most likely due to more conservation farming practices incorporated in recent years.