Speaking to a crowd of hundreds of precision agriculture professionals, University of Missouri professor Newell Kitchen called roll, asking how many were from a corn-growing region. About half the crowd stood.
Then he asked the audience to remain standing if they’re from an area with too much water, the bulk of them did, naming home areas including Minnesota, Wisconsin, and Manitoba.
“This year is a great example of the difficulty we have here,” Kitchen told the crowd. “If you’re of the culture of much of the midwest, where much of the nitrogen goes on early or even the fall before, you’re likely hurting right now.”
The reason, he said, is that nitrogen loss is a nearly constant reality through the Midwest--and some generally-accepted models to apply nitrogen need reexamination.
Stop the tape. Play it back six hours.
Before the opening keynote of Info Ag, honors were awarded to several industry players including Newell, who received the Legacy Award:
Moderator Paul Schrimpf hailed Kitchen’s decades of work in Missouri:
He’s been working in precision agriculture “long before anybody called it precision agriculture,” Schrimpf said. “Nitrogen needs differ by as much as 89 pounds an acre...A lot of these concepts are understood now, but Newell was doing the foundational work.”
Schrimpf wasn’t exaggerating. Kitchen, who works with the USDA Agricultural Research Service, has published more than 100 pieces of research, with 4,600 citations.
Now let’s roll that original tape again.
The legacy award winner Kitchen is again rocking the boat, pointing out the shortcomings of current nitrogen models.
“Grower surveys often list nitrogen management as one of the most challenging decisions in modern corn production,” Kitchen told the crowd. “When applications are over 30 pounds over (Economic optimum N rate), just about every pound of nitrogen applied is nitrogen lost.”
Around the country, he said, that amounts to 585 barges of Urea-N that’s estimated to be overapplied each year.
“So the question is, how do we make these decisions?” Kitchen asked. He named several empirical-based models like the popular Maximum Return to Nitrogen or MRTN, along with crop growth models, soil tests, and sensing.
Kitchen worked with a group of other academics to study 49 different areas around the Midwest from 2014 to 2016, evaluating how well existing models work.
“MRTN is used quite a bit, but with this dataset it doesn’t do very well,” he said. “Iowa PSNT looks a bit better. If you get to adapt (application plans) in-season with different kinds of tools, you’re a little better off.”
Then he presented the next twist to the research.
“What if you took seven different tools and instead of using them independently, thought of them as tool fusion?” Kitchen asked.
He showed a decision tree that started with the Iowa PSNT tool, then moved on to other techniques of nitrogen management.
With the decision tree used to adjust application, the fit to optimal levels was much better.
“There’s still errors, sites that deviate off that line, but you’re getting those sites much closer to that line. So this has some promise,” Kitchen said. “Alone, these tools did not work very good, but if you start stacking these tools..you’re going to get a better response.”
Kitchen acknowledged the study was not the end-all-be-all. In fact, he said, the team he worked with is still publishing results, and key findings will be released over a period of months or years.
Growers and crop consultants alike will want to keep an eye on the work.
“It’s not going to solve all the questions we have about nitrogen, but it’s going to push us in the right direction,” Kitchen said. “ If we don’t do it, nitrogen regulation is going to be facing us more and more. We have to be responsive and do the best job we can.”