Learn strategies to protect water quality at Martens farm field day – June 15, near Winterset

For Release: June 3, 2015

WINTERSET, Iowa — Keeping nitrogen in farm fields and out of adjacent waterways is always the intention when applying fertilizer to crops. This isn’t always possible, due to variable weather and other factors outside a farmer’s control. But while runoff and leaching may not be entirely preventable, there are many ways farmers can minimize how much nitrogen enters local streams. One approach is to build a nitrate removal wetland.

“The interaction between warm water and foliage creates a denitrification effect,” says Frederick Martens, who farms 1,000 acres of crop ground with his father near the headwaters of Badger Creek. “Since putting in our wetland and prairie, this place has become a magnet for natural life. And it really didn’t take that much land out of production compared to the benefits we think we’re giving to the watershed.”

The Martens are in their fourth year using a nitrate removal wetland, and invite farmers and the public to learn more about how it works at a Practical Farmers of Iowa field day they are hosting on Monday, June 15, from 2-5 p.m., near Winterset. The event – “Multiple Benefits from Wetlands, Prairies and Cover Crops” – is free to attend, and will also highlight other strategies Frederick and his father are using to protect water quality, which include using cover crops and building terraces. The farm is located at 1218 U.S. 169, about 4 miles south of De Soto or 9 miles north of Winterset (look for a big, red barn on the east side of the highway).

The field day is sponsored by Iowa Environmental Council, Madison County Soil and Water Conservation District, Organic Crop Improvement Association International and Whole Foods Market.

In addition to giving a tour of the wetland and adjacent prairie, Frederick will share his experience with cover crops and grid-sampling for variable-rate planting and fertilizer application. Anna MacDonald, project coordinator for the Badger Creek Lake Watershed, will help host the field day and discuss efforts to improve water quality in the watershed. She will also help attendees identify prairie plants growing in the Martens’ prairie.

Other speakers will include Matt Helmers, professor of agricultural and biosystems engineering at Iowa State University, who will talk about the role of conservation practices in reducing nitrate losses. Jessie Lowry, conservation manager at Blank Park Zoo, will speak about the zoo’s Plant.Grow.Fly initiative to increase the amount of pollinator habitat. “Blank Park Zoo will try to plant milkweed at our wetland to try to get a food source for monarchs, which will be a learning experience for me too,” Frederick says.

He adds that he’s particularly excited to talk about the nitrate removal wetland because of how successful the system has been so far. “With buffer strips and all, it’s only about 17 acres – but about 700 acres of crop ground drain into it.

“Anna did some water tests earlier this spring and took a sample out of one of the big tile lines that dumps into the wetland. It was 10 parts per billion (ppb). She then took sample of water coming out of the wetland, and it was 3 ppb. That’s unofficial and was her strip test, but that to me proves how well it works.”

Practical Farmers of Iowa’s 2015 field day season features 40 field days around Iowa. All field days are open to the public, and most are free to attend. The guide is available online at practicalfarmers.org, or contact the PFI office at (515) 232-5661 to request a printed copy.

Practical Farmers’ 2015 field days are supported by several sustaining and major sponsors, including: Albert Lea Seed; Applegate Natural & Organic Meats; BlueStem Organic Feed Mill; Center for Rural Affairs; Featherman Equipment Company; Grain Millers, Inc.; Iowa Agriculture Water Alliance; Iowa Beef Center; Iowa Farm Service Agency (USDA); Iowa Farmers Union in partnership with Town and Country Insurance and Hastings Mutual Insurance; Iowa State University Department of Agronomy; Iowa State University Extension and Outreach; Iowa Sustainable Agriculture Research and Education (SARE); Iowa’s Center for Agricultural Safety and Health (I-CASH); ISU Graduate Program in Sustainable Agriculture; Klinkenborg Aerial Spraying and Seeding, Inc.; La Crosse Seed; Leopold Center for Sustainable Agriculture; Midwest Organic and Sustainable Education Service (MOSES); MOSA Organic Certification; National Wildlife Federation; Natural Resources Conservation Service (NRCS); Organic Valley – Organic Prairie – CROPP Cooperative; The Nature Conservancy in Iowa; Pro-Soil Ag Solutions; Wallace Chair for Sustainable Agriculture; and Welter Seed and Honey Company.


Founded in 1985, Practical Farmers of Iowa is an open, supportive and diverse organization of farmers and friends of farmers that seeks to strengthen farms and communities through farmer-led investigation and information-sharing. Farmers in our network produce corn, soybeans, beef cattle, hay, fruits and vegetables, and more. For additional information, call (515) 232-5661 or visit www.practicalfarmers.org.


Anna MacDonald | Badger Creek Lake Watershed | (515) 462-2961 ext. 3 | Anna.MacDonald@ia.nacdnet.net

Tamsyn Jones | Practical Farmers of Iowa | (515) 232-5661 | tamsyn@practicalfarmers.org