3 panelists at Minnesota nitrogen conference
N INSIGHT: Panelists at the annual nitrogen conference include crop consultant Rick Gilbertson (center) and Extension educators Dave Nicolai and Anne Struffert.

On top of N

Panel discusses nitrogen-use opportunities and challenges in 2018.

The 2017 growing season is a fond memory for many, including yields that helped Minnesota growers set a record of 194 bushels per acre. Farmers also saw overall good yields for soybeans, sugarbeets and alfalfa.

As usual, the weather had its say throughout the season. Growing degree day units could have been better, for one.

Looking ahead to this growing season, a three-person panel at the fourth annual Nitrogen: Minnesota’s Grand Challenge and Compelling Opportunity Conference on Feb. 6 in St. Cloud offered a cross-section of suggestions for crop management.

Panelists were Dave Nicolai, University of Minnesota Extension educator in crops; Rick Gilbertson, president of Pro Ag Crop Consultants, Sauk Rapids; and Anne Struffert, U-M Extension educator in water quality, St. Cloud.

Acknowledging the gamble with weather, Nicolai, who discussed agronomic opportunities, encouraged growers to select hybrids that would mature two weeks before the killing frost date. Stalk rot adds to that challenge of matching maturity with potential harvest dates, he said.

“Keep overall disease resistance in mind,” Nicolai said, noting that soybean growers in south-central Minnesota had challenges with white mold last year, due to a wet and colder-than-normal July.

“There are benefits to fungicides, but they need to be applied early enough,” he said. “So if you had white mold last year, keep that in mind this season.”

He acknowledged the challenge of early tillage to remove early waterhemp and giant ragweed. “Waterhemp has resistance, so you do need to stay on top of it,” he said.

Nicolai also recommended early corn planting by the last week of April and a seeding rate of 34,000 seeds per acre for optimal economic yields.

Gilbertson, speaking on opportunities for crop consultants in the audience, said that working more closely with livestock clients on nitrogen management would pay off.

“We need to work with them to capture as much free nitrogen as possible” from livestock manure, he said.

Gilbertson also gave a plug for applying the right source of N at the right time.

“If a grower farms 6,000 acres in seven counties with an average field size of 65 to 70 acres to manage, you’re kidding yourself and the farmer, too,” about blanket timing and source of nitrogen, he said. “You need a safer approach — for example, using a stabilizer or applying N as a sidedress. If you can’t make a sidedress and only have one-third of your N on and 30,000 seeds planted, you’re going to be in big trouble, especially if it rained.”

Later he added that multiple N applications in a timely fashion are a great way to improve N efficiency.

“You need to know when corn N uptake occurs,” he said. “By eight to 10 leaf collars, if you don’t have enough N on, leaves will be yellow and you’ve lost bushels.”

For the upcoming season, Gilbertson sees giant ragweed and waterhemp as the usual troublesome weeds. Growers may see other weeds such as pennycress, shepherd’s purse and dandelions.

“If you’ve got dandelions, you do have a crop-limiting problem,” he said.

He advised farmers to follow a more prescriptive approach to weed control and not spray the whole field with one control for all.

“If you get giant ragweed, till it up and then plant soybeans,” he said. “You’d be better off.”

As a technical adviser to help the Minnesota Department of Agriculture roll out the new nitrogen fertilizer rule later this year, Struffert gave an overview of the program.

Basically, the proposed rule has two parts pertaining to farms: following fall and frozen soil restrictions if located in vulnerable groundwater areas, and following best management practices in areas that have high concentrations of nitrate in groundwater. If a farm is located in such an area, it would have to follow specific rules for mitigation, or reduce the severity of the nitrate problem.

MDA held 11 listening sessions last year and gathered more than 800 comments. Five themes emerged from those who responded:

 definition of vulnerable groundwater areas

 need for additional water sampling, after concerns were expressed regarding the accuracy of homeowner-submitted water samples

 acknowledgement of exceptions to fall restrictions

 pace of program regarded too slow to regulate

 concerns that regulations were based on fear not water quality

On March 6, Gov. Mark Dayton and Minnesota Ag Commissioner Dave Frederickson released a proposed draft of the nitrogen fertilizer rule. MDA expects the rule to be published for formal comment in mid-to-late May with hearings to be held this summer and final adoption in late 2018. Additional information on this will be provided in an upcoming story.

TAGS: Soil Health
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