Clean Water With Kernza
Research from the U of M contributed to the city of Edgerton’s test planting this perennial grain to reduce nitrates in its well.
Ed. Note: The U of M’s Forever Green Initiative (forevergreen. umn.edu) is a College of Food, Agricultural, and Natural Resource Sciences research platform that’s developing and improving annual and perennial crops and systems that protect soil and water and drive opportunities for growers, industry, and Minnesota communities. The group studies 16 crops, including Kernza. This story first appeared in the August 17 edition of The Land, a division of Mankato, Minnesota’s Free Press. www.TheLandOnline.com
Kernza is gaining traction as an alternative crop which aids in the quality of soil health, but a Minnesota community is using the perennial grain to protect its water supply.
Kernza is the trademark name of a grain developed by The Land Institute in Salina, Kansas. It’s described as an intermediate wheat grass, dveloped from a wild perennial grass. It’s the first perennial grain crop in the United States.
The grain is being tested, improved, and promoted as a new crop by numerous collaborators in the United States, Canada, and Europe, including the U of M's Forever Green Initiative—a leader in improving and commercializing the grain. According to an MPR news report last September, 1,300 acres were grown in Minnesota—over a quarter of the total acres in the U.S.
Thirty-eight acres of Kernza grow on the northwest corner of Edgerton in south-western Minnesota. It wasn’t planted by a farmer trying the new grain, but by the city of Edgerton. It’s in the city’s wellhead protection area. The city gets its water from that well, and this is part of its effort to reduce nitrates in the water.
Edgerton’s wellhead protection area is about 600 acres, but the city doesn’t control all of that.
“We rent 125 acres from a retired farmer,” explains Doug Brands, water supervisor for the city. “We put in 38 acres of Kernza closest to the wellhead; the rest of it we put in small grains, like cereal rye and oats.”
Nitrates are the only contaminant for which the city needs to treat its water. Working with Aaron Meyer of the Minnesota Rural Water Association, who knew of the Forever Green Initiative, city officials contacted the University.
“Through trials, the University discovered that this is a really good crop above a well-head area, because it uses so much nitrogen that it filters it out before the water hits the aquifer,” Brands says.
The filtering quality comes from a root system that runs 10 or more feet into the ground. It also has the benefits of other perennials, such as sequestering carbon, stopping erosion, and building soil health.
Kernza was planted for its ability to use nitrogen, but there’s also an annual crop for the city to harvest.
“There’s no challenge to marketing the hay,” Brands says. “Every farmer likes the hay. That sells right away.”
Selling the grain is the challenge. “It’s at that in-between stage,” he says. Production is not large enough for the big players, but more than can be used by bakers and craft brewers.
The first year, Brands sold the crop to the University for seed, where research continues to improve the grain and promote marketing. The next two years’ production of 18,000 pounds is in storage. This will be the fourth year of what’s considered a three- to five-year life span.
“It has a massive root system and just kind of gets rootbound,” Brands says. He saw a reduction in yield last year. What happens after five years?
“How long I continue is to be determined,” Brands says. “The University does a lot of studies, and I might wait to see what they recommend.”
As for its filtering ability, that’s been proven over the first three years.
“The nitrate limit for safe drinking water is 10 parts per million,” Brands says. “We are now in the 12-14 ppm range, down from 20-22 ppm. That’s a 30 to 40 percent drop.” Which means less treating of the water, which saves money.
Saving money and earning money from
the harvest are helpful, because ensuring
the city has safe drinking water costs money.
Edgerton has received assistance for its
efforts: The Minnesota Rural Water Association, Minnesota’s Clear Water Fund, Pipestone SWCD, and the Minnesota Department of Health Water Source Protection
grants have all played a role. A Minnesota
Board of Water and Soil Resources wellhead
protection partner grant made possible the
purchase of 38 additional acres north of the
well that will be seeded to grass.