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When Glen Groth started his farming career 13 years ago, he knew he wanted to utilize the knowledge of local agronomists to give his business an advantage. He found the partners he was looking for at Farmers Elevator (now Farmers Win). He credits his co-op and its agronomists for teaching him how to use fertilizer and crop protection inputs. Now he is repaying the co-op with in-field data on nitrogen utilization test plots they can pass on to other customers, helping them increase yields while reducing N loss and helping protect the environment. 


Groth, who farms with his wife Melinda near Ridgeway, Minn., says, "They earned my business, and I've stuck with them. I use their grain drying and storage services, fertilizer application, seed sales and more."


"We get involved in pretty much all of Glen's work," says Erik Dahl, agronomist, Farmers Win. "The work we do with him can be transferred to other growers we work with, as well as shared with other Farmers Win agronomists at our winter meetings." 


Dawn Bernau, Minnesota Department of Agriculture's Nutrient Management Initiative lead for southeast Minnesota (left) works with Fillmore SWCD technician Sara West (center), and Farmers Win Co-op agronomist Erik Dahl (unpictured) to support landowners Glen and Melinda Groth in their effort to increase nitrogen use efficiency on their farm. Here, Bernau takes soil plant (chlorophyll) analysis development (SPAD) readings and shares results related to nitrogen deficiency with Glen Groth (right).

That work includes a wide variety of product, rate and application timing studies. This year Groth is continuing some split applications, evaluating the benefits of nitrogen stabilizers and doing replicated trials at different rates. Dahl and Rushford, Minn., location manager Justin Brown get involved to some extent in all of the above, both at application and at harvest, when they provide weigh wagons for accurate data gathering. 


Many of his fields are considered highly erodible land (HEL), and Groth has enrolled 300 acres in the state's Conservation Stewardship program for a second year. As part of it, he is working with no-till and cover crop practices on some of his fields. 


"If it were dry every year, I would be no-till on all my fields," says Groth. "However, my fields are spread out with lots of wet spots, and I still have to do tillage to get crops in early, but I don't do any more tillage than I have to. I believe in no-till and do it on a third to half my acres."

Groth's experience with cover cropping has been positive, but he is still evaluating its place in his program.


"Last year I planted soybeans green in six-foot tall rye, and it produced some of our best beans," he says. "However, last fall the soil froze up too soon to get any cover crops planted. I think they do increase organic matter and nutrients, but they are an added investment, and you need a return." 


While he seeks high yields, he is also concerned about the impact his practices have on ground water and the Root River, Mississippi and Pine Creek watersheds his fields drain into.


Dawn Bernau uses a hand-held soil plant analysis development (SPAD) meter to quickly, accurately measure leaf chlorophyll concentrations in southeast Minnesota fields.The readings help Ridgeway, Minn. area farmer Glen Groth and others understand how much fertilizer is enough, and how and when to  best apply it.

Groth photo 3.JPG

Groth appreciates the co-op's variable rate application (VRT) services. He gathers some of his own soil samples, but relies on Farmers Win to do most of his grid sampling. They sample on 2 1/2-acre grids on his larger fields and composite samples on smaller fields. While still unsure if the variable rate fertilizer is providing savings or yield increases, he intends to continue.


"It is too early to see results yet," he says. "However, I do think it is good to invest in fertilizer where it is needed, and the people we rent from like to see that we are maintaining fertility."


Groth does a variety of test plots every year on his own, including split applications. This year he has a third partner in his on-farm research. He is working closely with Dawn Bernau, pesticide and fertilizer management, Minnesota Department of Agriculture. She manages the Nutrient Management Initiative (NMI) research plots in southeast Minnesota and its second stage initiative, The Southeast Minnesota Nitrogen BMP Outreach Program. Overall goals are to reduce nitrate groundwater contamination by increasing N use efficiency.


Bernau lays out replicated in-field plots that Farmers Win applies. They include his normal corn following corn rate of 165 lbs. N per acre, as well as rates plus and minus 30 lbs. and a high rate of 200 lbs. "We marked out the strips, and I rode with the applicator to make sure the rates were applied properly," notes Dahl. "Dawn then marked them with GPS so they can be evaluated throughout the season."


Justin Brown, Farmers Win Co-op location manager, Rushford, Minn., customer Glen Groth (center), and Erik Dahl, Farmers Win agronomist finish a quick analysis of Groth’s 2019 harvest. Corn kernels and rows on a number of ears suggest potential yield of 220 bu. per acre, assuming no frost until October 1.

The program includes intensive nitrogen sampling of soil and tissue at the plots, which will be carried out by Bernau and Fillmore Soil and Water Conservation District staffer, Sara West. This is Groth's first year in NMI and the SEMN N BMP Outreach Program; however, Famers Win has been participating in the NMI/SE BMP program since 2015 with other growers. They also did similar nitrate testing on Groth's fields in 2018. These were done at four different sites, including fields with corn following soybeans and corn-on-corn with manure and without. The results surprised Groth and Brown.


"We did soil nitrate testing at V5 and R1 (silking) stages, tissue sampling at black layer and end of season stalk nitrate testing," says Groth. "We want to be sure we are applying enough N, but we also want to do right by our water."


"Manured fields had plenty of N early, but not late, while fields that had not been manured stayed high throughout the year," says Brown. "The results go against what we expected. As a result, we are sidedressing manured fields this year."


"The results suggest we were underapplying, but it could have been a function of the wet year," says Groth. "We'll be doing more nitrate testing this year in hopes of benchmarking N rates."


Groth's research data is shared with Farmers Win and other farmers. "At the end of the season, we bring participating farmers together to go over their reports and discuss them," says Bernau. "We also hold field days in the summer that are open to the public."


"Through the test plots we are doing with Glen and Dawn, as well as others, we are learning and trying to apply that knowledge to make better decisions as we move forward," says Brown.


"Nitrogen utilization is an ongoing, learning process. With so many variables, you have to look at data and results over the years to truly know if you are going the right way."

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