Conservation in Action

Bioreactor Helps Filter Potential Pollutants

Matt Wilde
By  Matthew Wilde , Progressive Farmer Crops Editor
Conservation efforts were highlighted during a tour of Iowa farms and facilities as part of the Conservation in Action tour. Innovative tactics are helping farmers reduce runoff and nutrient loads that wend their way to the Gulf. (DTN photo by Matthew Wilde)

DES MOINES (DTN) -- More than 100 people from across the nation recently got an up-close look at the latest in conservation practices aimed at improving water quality from Iowa to the Gulf of Mexico.

Participants on the day-long Conservation in Action tour, hosted by the Conservation Technology Information Center (CTIC), learned how a bioreactor under construction on the Bill and Nancy Couser farm near Nevada, Iowa, will remove nitrates from water before it leaves the property. It was one of many conservation practices showcased that improves water quality and soil health.

Tour attendees climbed on a pile of woodchips, some even picked up a handful to smell, as Keegan Kult, executive director of the Ag Drainage Management Coalition, explained how the wood refuse will help people and the environment.

The project is still being built, but woodchips will eventually fill a 20 foot-by-120 foot plastic-lined excavated chamber that will be covered with dirt. Water drained from a nearby field by tile will be directed into the pit and treated before it flows into the waterway that's part of the Skunk River Watershed, which will eventually make its way to the Mississippi River and the Gulf of Mexico. Microorganisms on the woodchips will convert the nitrates in the water into nitrogen gas that is released into the atmosphere.

"People can expect a 30% to 60% nitrate load reduction from a bioreactor," Kult told the tour group. "It's one of the more cost-efficient practices for nitrate removal the public can invest in."

A bioreactor costs $8,000 to $12,000 to build. Landowners can often receive government cost-share dollars to offset the cost of edge-of-field and in-field conservation practices. A bioreactor typically services 30 to 80 acres for about 12 years before woodchips need to be replaced.

CTIC promotes and provides information on technologies and sustainable, productive and profitable agricultural systems that conserve and enhance soil, water, air and wildlife. The West Lafayette, Indiana-based organization, funded by agribusinesses, commodity groups and individuals, hosts an annual tour to bring people together from across the country to learn and talk about conservation practices and issues they don't see every day.

"People get a chance to see bioreactors, saturated buffers and cover crops ...things they can touch, feel and see," said Mike Komp, CTIC executive director. "Officials from industry, conservation groups and all levels of government come together to talk with farmers and each other about conservation to tackle challenges in agriculture."

TOUR STOPS

This year's expedition in central Iowa stopped at farms owned by the Couser family, Lee Tesdell near Slater, and the Iowa chapter of the Land Improvement Contractors of America near Melbourne. The group also toured New Century FS in Melbourne to learn about nutrient and chemical application and best management practices.

Each farm stop featured conservation practices designed to meet the goals of the Iowa Nutrient Reduction Strategy, a science-based plan approved in 2013 to reduce nitrate and phosphorus loads entering waterways by 45% from point and nonpoint sources. Other states in the Mississippi River Watershed have similar strategies with the ultimate goal of improving water quality and reducing the hypoxic or "dead zone" in the Gulf of Mexico that's largely void of aquatic life.

Komp said it was the perfect time to visit Iowa to learn how various conservation practices affect the environment and cropping systems during adverse weather.

Massive flooding occurred in the state this spring. Persistent precipitation delayed planting. Now, some parts of Iowa are abnormally dry or experiencing a moderate drought, according to the U.S. Drought Monitor.

Conservation experts and farmers told tour participants how wetlands and cover crops helped hold back water and nutrients in the spring from already full rivers. In addition, a combination of conservation tillage and cover crops builds organic matter and improves water retention.

"If I could control the weather, I would have this business whipped," Bill Couser told the group. "But I can't. That doesn't mean I won't continue to find a way to do it.

"I'm representing the American farmer here," he continued. "A lot of innovative things are going on. We want to be good stewards so the land is available to the next generation."

The Cousers, who farm with two sons, recently created a 220-acre AGvocacy Learning Farm in partnership with Bayer and other partners. It has six fields that reflect common farming landscapes throughout Iowa. A few conservation practices being studied include:

-- Cover crops: Crops, such as cereal rye, planted between periods of regular crop production to prevent erosion, increase soil organic matter and sequester nutrients.

-- Saturated Buffer: Water from a field tile is intercepted and discharged into an adjoining riparian buffer/filter strip via a lateral tile line. Studies show nitrate removal of 22% to 44%.

-- Bioreactor

-- Automated drainage water management: The water table is managed using control structures in the tile system. More water can be retained in the soil profile when needed. Studies show it can reduce nitrate and dissolved phosphorus discharge by 33% and 50%, respectfully.

Conservation measures will be monitored and benefits quantified. Results will serve to advance the state's nutrient reduction strategy and promote acceleration and adoption of practices.

"It's our data, but it will be shared with everyone," Couser said.

INFORMATION PUT TO USE

David Meyer, who works in predictive agriculture for Corteva Agriscience, wanted to see how conservation practices interact with different cropping systems so farms can become more sustainable.

"Our company is all about solving problems," Meyer said. "We look at what issues farmers face now and in the future to offer seed, technology and crop protection tools to help farmers and consumers."

Carrie Vollmer-Sanders, the North America nutrient strategy manager for The Nature Conservancy, said the organization has conservation projects in half the states. She attended to garner new ideas to keep nutrients on farmland and out of drainage tile and waterways.

That's why CTIC will continue the annual conservation trek, Komp said. "We want participants to learn from each other and go back across the country and make a difference," he added.

Matthew Wilde can be reached at matt.wilde@dtn.com

Follow Matthew on Twitter @progressivwilde

(PS/BAS/CZ)

Matt Wilde