What is erosion? Who is responsible? Where does it occur? Why does it happen? How much does it cost? Can we reduce it? These and other questions are addressed at an educational display in the Ohio’s Lake Loramie State Park vicinity. In the fall of 1996, an estimated 300 tons of dredging from the lake was piled on the south side of Ohio 119, between Luthman and Thaman Roads, about seven miles west of Interstate 75.

Sponsored by the Loramie Watershed Association and Lake Loramie State Park, the purpose of the demonstration mound and sign is to make everyone more aware of erosion and to better manage human practices that affect soil movement. The Ohio Department of Transportation estimates over 3,200 vehicles pass the mound each day.

Working with Ohio State University Extension Agricultural Engineer Larry Brown and others, members of the Loramie Watershed Assoc. developed representative display numbers using the following general assumptions: fall-plowed erodible land erodes at six tons a year, hay fields erode at one ton a year (established one year), no-tilled soybean fields erode at 1.5 tons a year (following corn), construction land erodes at 60 times that of tilled farmland, state highway average 80 feet of right-of-way, 20 feet is road and house lots average one-half acre in size, thus 17 lots times one-half acre equals eight-and-a-half acres. (The same slope was used on all examples. Ten percent eroded sediment leaves the site, a conservative estimate according to Dr. Brown.) A 20-foot-wide filter strip removes 80 percent of eroded sediment.

Are these numbers correct for all situations? Absolutely not! Soil type, slope length, vegetative cover and management techniques vary significantly. However, the assumptions help us compare man-made impacts equitably.

We suggest that the 300-ton mound represents potential annual soil loss due from erosion due to 1.14 miles of road construction, 17 house lots cleared for building, or 500 acres of fall plowed erodible land. On the positive side, 300 tons of soil is the potential annual soil savings from 1.25 miles of filter strips, 167 acres in no-till soybeans, and 83 acres in established hay.

Can we reduce man-induced soil erosion? We can and are.
Approximately three-fourths of our soybeans and wheat are now no-tilled. Cover crop use is gaining favor with increasing numbers of grain and livestock farmers. Over 400 miles of filter strips have been planted by farmers locally since 1997. The Ohio Department of Transportation is now required to use erosion control techniques for road building. Other construction sites now use soil loss management strategies. And the list goes on … what are you doing to preserve our soil?

The views and opinions expressed in this column are those of the author and not necessarily those of Farm World. Readers with questions or comments for Roger Bender may write to him in care of this publication.

Published on Sept. 30, 2009