STORY BY JIM RUEN for NewGround
Glen Haag has more questions than answers when it comes to nitrogen (N) utilization, but that hasn't stopped him from looking. He and his farming partner and father-in-law Dave Ruprecht work with plant tissue tests, soil nitrate and end-of-season stalk nitrate tests, split application of N, cover crops and no-till. This year the Lewiston area farmer began working with his Ag Partners agronomist Justice Keefauver on a new program to tie fertility and organic matter together. For the past five years Haag has worked with University of Minnesota Extension Educator Jake Overgaard on nitrogen rate trials. His search for data on nitrogen utilization is both personal and professional.
"I'm an outdoorsman, and like a lot of farmers who are, I want to protect water quality," says Haag.
Nitrogen utilization rate trials conducted with University of Minnesota Extension help the Haag family run a profitable farm business with minimal environmental impacts. In this photo, Extension educator Jake Overgaard and Glen Haag share what they're learning with visitors at a 2018 field day. (Photo: Cory Ryan for University of Minnesota Extension)
A member of the Whitewater Watershed Farmer-Led Council, Haag's varied efforts have brought impressive results. "Glen is on the leading edge of our precision platform in regard to nitrogen efficiency," says Keefauver. "In 2018 his corn utilized on average 0.72 pounds of total applied nitrogen per bushel of yield, but he is still trying to better understand what his soils can do and how he can maximize yield while protecting the environment from nitrate movement."
Ag Partners is working with him in that effort. It is Haag's first full year with the cooperative. "We learned what he has been doing, his concerns for the environment, his goals for production and getting there without the overuse of fertilizers," says Keefauver. "Based on that, we made some recommendations, including urea coated with ESN, a flexible polymer, and some N stabilizers to see if he can reduce the total pounds of N per bushel even more."
The ESN coating reacts to soil temperature to release N in solution to meet the crop's growing demands, while the stabilizers keep the N in the profile where roots can absorb it rather than it moving down into groundwater. Haag likes the idea of the blend of standard urea for early pop-up and ESN for slower release. As part of the evaluation, Keefauver is running a series of soil nitrate tests for Haag. Samples were pulled at 0-12 and 12-24-inch depths preseason and again at the V4 growth stage to determine the location of available Nitrogen.
Ag Partners agronomist Justice Keefauver (left) works with Glen Haag to meet production goals while respecting his desire not to overuse fertilizers. His recommendations have included using urea coated with ESN and some N stabilizers to help reduce total pounds of N per bushel.
One of the challenges Haag faces is matching N rates to his use of manure. With 450 Holstein steers on feed, he has a lot of manure to spread. Nitrogen rate trials conducted with Jake Overgaard, now in their fifth year, are a valuable source of data for Haag. Overgaard lays out replicated plots of zero added N as checks, what Haag would normally apply, rates 30 lbs. above and below the normal rate and a high rate. This year the tests will include the ESN urea blend.
Overgaard also runs soil nitrate tests preseason, at V4 and post season, as well as stalk nitrate tests on the plots. He appreciates being able to partner with Haag on the plots for more than just data gathering.
"Glen really wants to improve his N management for the environmental benefits, but with a strong eye on economics and managing to the best of his ability," says Overgaard. "I know the findings we get will factor into what he does and help him make changes."
What Haag typically does is apply up to 180 lbs. of N per acre on corn-on-corn fields and 150 on corn following soybeans, depending on how much manure was applied. "Some years the results have been mind boggling," says Haag. "The optimum rate is usually between 150 and 180 lbs."
Managing nitrogen with a manure application is challenging when samples are variable, notes Haag. The number of years a field has been manured, the application method and timing, and the results from the manure samples help play a role in decision-making.
"Organic matter makes a huge difference in how much N it gives back," says Haag. "We have had plots with the right temperatures, the right rain and the right organic matter where zero added N was the optimal rate."
This may not be one of those years. On manure applied fields, the early soil nitrate tests showed 200 lbs. available N in the top two feet. Whether it sticks around during the growing season depends on the weather.
"Last year we saw a big drop between preseason tests and V4," says Keefauver. "Based on weather patterns this spring, I expect we lost quite a bit."
While it doesn't account for potential N release from organic matter, Haag is looking forward to evaluating the soil nitrate test data and comparing it to other sampling he has tried. He has seen mixed results in some cases or too much variability in others; however, he continues with trials.
Whether or not he has found the answers he is looking for, Haag is confident in the value of the search. "I think the biggest thing is to get involved in available programs and experiment on your own farm," he says. "Everyone's place is different, which is why we do all these trials on our own ground. We can see what's going on, analyze and adjust."