On a muggy July day, Tim McMahon leans into a ground-level black box at the edge of a Macon County farm. Balancing a black laptop, lengths of pipe and several other tools, he draws out small samples of water and deposits them in clear containers.
McMahon is watershed specialist for the Agricultural Watershed Institute, an organization that researches and demonstrates ways to reduce erosion and manage the nutrients that affect bodies of water. On this day, he is testing water from a farm drainage system.
The owner of this farm, John Heller, has allowed researchers to install a “bioreactor” designed by Professor Richard Cooke from the University of Illinois and made up of woodchips at the end of the drainage system.
“We’re forcing the water through that volume of woodchips. As it does that, the woodchip will attach nitrate to it, and you have denitrification,” McMahon said. “We’re pulling water from both the inlet side and the outlet side … to test the level of nitrates in the water.”
Meanwhile, on a plot of land at Progress City USA, AWI is also growing a variety of grasses that could help remove nutrients from water in soil before it makes its way into ground water or creeks and ditches. Those grasses could also provide fuel, explained executive director Stephen John.
“These grasses can provide clean water, wildlife habitat and renewable energy,” John said. “At the University of Iowa, they’ve started to grow several thousand acres of miscanthus, and they’re burning it along with coal in the University of Iowa power plant.”
John said AWI is working with farmers to plant plots of grass on land that may not be easily farmed for other crops.
“We may be in a way going back to the future,” John said. “We may be going to a landscape that, yes, has 80 to 90 percent of farm acres in corn and soybeans, but say 10 to 15 … in some of these perennial grasses that can really provide some of these water quality benefits.”
Still, he said, doing so would require new markets for grass as biofuel.
