Bioreactor on Gorans Farm focus for U research
WILLMAR — The search for ways to keep nitrates out of the state’s waters has led researchers to the shores of Lake Wakanda in Kandiyohi County, where summer algae blooms speak to the importance of this quest.
Since 2010, researchers with the University of Minnesota and the United States Department of Agriculture’s Agriculture Research Service have been testing whether a bioreactor can help reduce the nitrates carried by water in tile lines on the Gorans Brothers Farm on the shores of Lake Wakanda south of Willmar. Before the water can leave a 179-acre field on the farm, it is pumped into the bioreactor. It is a 360-foot-long, earth-covered trench filled with wood chips. Microorganisms in it convert a portion of the nitrate to nitrogen gas.
“We’re very excited about this project,’’ said Mike Sadowsky, co-director of the University of Minnesota’s MnDRIVE or Minnesota’s Discovery, Research and Innovation Economy program.
There is hope that bioreactors could prove to be a practical means for keeping excess nitrate from leaving farm fields.
Sadowsky was among a team of researchers who led a tour last week of the Gorans Farms bioreactor. It is the first of 10 Discovery Farm sites currently in the state, where researchers collect data and conduct tests in the real-world setting of an operating farm.
Two things have been learned since research began on the farm in 2006. Even with the best of farm management practices, there are elevated nitrate levels in drainage water, according to Carl Rosen, head of the U of M’s Department of Water, Soil and Climate.
And, bioreactors aren’t always efficient. Microorganisms slow down when it’s cold, and Minnesota has a lot of cold.
“Bioreactor performance is poor when the temperature is cold,’’ said Ehsan Ghane, who knows that cold well. Rain, snow, sleet and brisk winds have greeted Ghane often as he and his fellow researchers in the U’s Department of Water, Soil and Climate have worked on the Gorans Farm bioreactor.
Their work now is focused on ways to enhance its performance. One idea being tested is to add acetate to the wood chips. The wood chips provide carbon needed by the microorganisms. Acetate is a readily available carbon that the microorganisms prefer and can use when temperatures are cool, Ghane said.
Researchers are also testing whether they can populate the wood chips with cold-tolerant microorganisms. They are taking samples of the microorganisms from the bioreactor back to the laboratory and selecting for the most cold hardy. The goal is to grow large populations of these desired bugs and add them to the bioreactor to monitor their performance.
The researchers will continue to work on the bioreactor for a number of years, and it will take time before it is known whether this technology will have a role on farms. Sadowsky said the project represents an example today of how researchers can work together with farmers to solve environmental problems.
“There are a lot of things going on on this farm,’’ said Carl Rosen, head of the University of Minnesota’s Department of Water, Soil and Climate. “The bioreactor is just one piece of the puzzle.’’
The farm is the Gorans Brothers Farm south of Willmar, where Rosen welcomed visitors last week who are interested in its bioreactor.
Research underway on the Gorans Brothers Farm is helping answer many questions involving water quality and modern farming, according to Kim Gorans, one of 10 partners in the operation. The farm includes 4,000 cropped acres and 60 turkey barns. They apply turkey manure from the barns as fertilizer on 10,000 acres of land.
Gorans said his initial interest in opening the farm to research was triggered by his frustration with regulations he said treated turkey manure as if it were a toxic waste. Research began here in 2006.
Some of the research has focused on the attributes of turkey manure compared to commercial fertilizer. From an environmental standpoint, Gorans said a three-year study found no difference in the water discharge.
Research on the farm has also showed how difficult it is to keep nitrates from water. On one field, the farm has not applied any fertilizer for 10 years. Nitrate runoff remains elevated, while corn yields have declined by half, he said.
The summer algae blooms on Lake Wakanda also played a role in Gorans’ interest in research. Many complained that farmland runoff was to blame, but Gorans knew that stormwater runoff from much of Willmar also makes its way to the lake.
Gorans said a report is now being drafted telling what researchers learned when they looked at the waters of the lake. He told participants at the June 2 field day that one of the big takeaways from that work was the discovery of ammonium nitrogen in the water. Its presence suggests the possibility that wastewater in the city’s sanitary sewer lines is leaking and being carried away in the stormwater lines during big rain events, he explained.
Other research is looking at how precision farming technology is allowing the farm to minimize its nitrogen applications on fields. One software package is allowing the farm to spoon feed nitrogen to corn. A computer program monitors rainfall, temperatures and the corn’s growing stage to precisely determine the quantity needed.
The farm is also applying tillage practices that Goran said are “better than the plow,’’ providing better growing conditions for the crop while greatly reducing erosion.
“They’re always looking for something different or better to be more efficient,’’ said Dan Haubrich, a crop consultant to the farm since 2012, during discussions at the field day.