Iowa City man develops erosion-control method
By Marlene Lucas
PANORA, Iowa -- Now that he's captured the attention of the U.S. Department of Agriculture, Iowa City lawyer John Nolan believes he is a step closer to helping farmers reduce erosion in gullies.
Nolan has been working on a method of gully remediation for 10 years, prompted by a desire to repair a 20-foot-deep ditch on farmland he manages. He received a patent in November for his Silt Terrace Erosion Prevention, or STEP. It's a simple idea: using dirt-filled plastic bags strategically anchored in a "V" shape in gullies.
The USDA's research arm is interested. Last month, five USDA Agricultural Research Service officials took a look at Nolan's STEP system.
The researchers stood in the gully and listened as Nolan described how water pools, drops its silt load and then pours over the STEP.
Sean Bennett of the National Sedimentation Laboratory in Oxford, Miss., questioned the source of the silt in the gully. He suspected the force of the water falling from the STEP was scouring soil from the gully and carrying it to the next STEP.
Nolan said the silt comes from higher up the watershed.
"It's from a farmer's plowed field north of here. I'm getting his soil," Nolan said.
Nolan had brought 50-pound bags of turkey feathers to anchor at the STEPs. He had read an Agricultural Research Service report saying barbs on the feathers will filter farm chemicals from water.
Weltz said Nolan's novel method has some application, but "one size will not fit all. There may be steeper river beds or higher velocities that it won't work with. That's part of research.
"Its real advantage is it can be cost-effectively applied. No special tools are needed."