For a sugarbeet grower, when someone tells you that you can reduce your nitrogen fertilizer inputs and costs by 20 percent and increase your crop quality and sugar yield, there’s only one logical response.
Prove it.
That’s just what the Western Sugar Cooperative set out to do with a Western SARE Professional + Producer grant after changes to the sugarbeet production practices raised the question of how much added nitrogen the crop really needs.
“Nitrogen is a pretty expensive input and has a pretty significant environmental impact because it's very carbon-intensive to produce and it has pretty big carbon impacts following application,” explained Rebecca Larson, the chief scientist and vice president of government affairs for the cooperative. “But it's also a critical component of crop production. If you don't put enough nitrogen down, you can't maximize your land-use efficiency, which also has negative environmental impacts.”
And sugarbeet growers have another added challenge: too much applied nitrogen actually reduces the sugar content in the beet and increases impurities, making sugar extraction harder still. Both reduce sugar yield and growers’ potential income.
What raised the issue of how much nitrogen to apply was the development and widespread adoption of glyphosate-resistant sugar beets around 2009.
“Our growers fundamentally changed their production practices with the adoption of glyphosate-resistant sugarbeets,” Larson said. “It was the first time sugarbeet farmers were ever able to really control the weeds in their field. Suddenly, they had fewer weeds competing for water and nutrients.”
But did that lack of competition mean growers were now putting down too much fertilizer?
To answer the question, the cooperative hired a scientist at the University of Nebraska, Dr. Bijesh Maharjan, to look at the ideal nitrogen application rate. He determined growers could support 35 percent higher yields with 20 percent less nitrogen.
“It was really cool to see in a 110-square-foot experimental plot,” Larson said. “But if you're a farmer managing 110 acres, it’s a big risk to cut your nitrogen that much.”
But the Western SARE funding took the risk out of the experiment. The cooperative used the $75,000 grant to incentivize growers in each of the cooperative’s four states – Colorado, Nebraska, Wyoming and Montana – to split a field in half and manage one half using their current nitrogen regime and the other half at the 20 percent reduced rate.
It worked, generally.
“What we learned is that it's not quite as simple as ‘one size fits all,’” Larson said. “But by doing this initial test, we could see it works more often than not. Mother nature is sometimes not kind and there were lots of confounding variables that impacted the results .”
Understandably, growers weren’t about to bet the farm and change practices after just one year of results.
“Yeah, they’ll say, ‘Okay, you got it to work that year, but maybe we were just lucky,’” she said.
The results were encouraging enough for the cooperative to get two additional grants, a Conservation Innovation Grant and a subaward from Edge Dairy Cooperative’s Partnerships for Climate Smart Commodities grant to replicate and expand the initial split-field experiment.
“With these two grants, we're now testing the reduced rate on over 100 farms over four years to see if we get this consistently to work over a large geography under various environmental conditions,” Larson said. “If the answer is yes, I think we'll see all that skepticism cast aside and the growers will move forward with this. Because not only are they saving money on fertilizer, but we're also showing that they're able to grow a better crop.”
And the economic potential is substantial.
“If we can get just a one percent higher sugar yield by improving nutrient stewardship, that's worth $20 million to our cooperative,” Larson explained “It's money on the front end saved and money on the back end earned – which every grower in this current market environment needs.”