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Mind nitrogen to manage costsMind nitrogen to manage costs

K-State reminds wheat growers to account for the nutrients already in soil banks.

Jennifer M. Latzke

September 6, 2022

3 Min Read
Lucas Haag, associate professor and K-State Research and Extension agronomist, Colby, Kan.
NITROGEN NEEDS: Lucas Haag, associate professor and K-State Research and Extension agronomist, Colby, Kan., speaks at the Wheat Rx meeting in Phillipsburg on Aug. 9. Haag covered fertility recommendations for wheat growers. Jennifer M. Latzke

Managing soil fertility is a critical component for farmers looking to manage their costs of production. In times when nitrogen or phosphorus might be expensive on the market, it’s tempting to pull back on fertility programs. But that could be a mistake, said Lucas Haag, associate professor and Kansas State University Research and Extension agronomist at Colby.

At the end of the day, there’s still no other crop input for wheat farmers than nitrogen that offers as high of a return on investment, and the economic penalty of being short is pretty steep, Haag said during a Wheat Rx meeting in Phillipsburg on Aug. 9.

And if the wheat market is evolving to start rewarding growers for protein in their wheat, he said the economic penalty for being short on nitrogen can be greater than what you save in application. The key is knowing what your soil already has available, and applying at rates that either maintain that soil fertility or build it in your soil bank for future crops.

Know before you apply

Kansas growers may be used to just applying a standard rate of nitrogen for their wheat crop, but they could be over- or under-applying for the crop’s needs. That can be expensive, Haag said. He offered up some points growers should consider as they’re figuring their application rates:

  • How much nitrogen does the crop need to meet its yield goal?

  • How much nitrogen is in the soil profile?

  • How much organic matter will be mineralized?

  • How much nitrogen could be volatized?

  • Will we have carryover nitrogen from soybeans or alfalfa or another nitrogen-fixing crop?

“What we’re left with is our nitrogen recommendation to make sure we’re meeting the maximum uptake needs of that crop,” Haag said.

In an Aug. 25 Agronomy eUpdate from K-State, Dorivar Ruiz Diaz, K-State nutrient management specialist, reminds farmers who have soils prone to leaching to consider the timing of their soil tests. Soil test values from the fall may be different from those in the spring, due to leaching over the winter in these soils.

Ultimately, failure to account for the nitrogen already in your soil can waste the resource, and cause crops to put on excessive foliage, increase susceptibility to plant diseases, inefficiently use soil water and reduce their yield, according to Ruiz Diaz.

Haag also reminded growers to be realistic about yield goals for their region and their soil types. “Taking your highest, best yield ever raised and tacking another 10% onto that, that’s probably not the most economical yield goal,” he said. Instead, shoot for something in between, he added.

Phosphorus removal

Haag also reminded growers that wheat needs adequate phosphorus before it can respond to nitrogen. And he said growers who have recently changed up their crop rotations to include more soybeans, rather than traditional wheat-fallow-wheat rotations, should review their phosphorus removal rates in their nutrient equations. It’s easy to underappreciate how much a good 40- to 50-bushel soybean crop can remove, he said.

“Wheat responds well to starter phosphorus, especially when late-planted,” Haag said. If you’re planting the wheat later, after you’ve harvested soybeans, you can maximize your response to starter phosphorus, he added. And the more frequent wheat appears in a cropping rotation, the more farmers should consider their phosphorus applications.

Ultimately there are obvious economic implications for dialing in the right fertilizer applications, Haag said, but there are environmental implications as well.

Many larger grain companies are trying to get a handle on carbon footprints of the crops they trade. Wheat farmers can help those companies and themselves by showing that they are managing their nitrogen and phosphorus applications.


About the Author(s)

Jennifer M. Latzke

Editor, Kansas Farmer

Through all her travels, Jennifer M. Latzke knows that there is no place like Kansas.

Jennifer grew up on her family’s multigenerational registered Angus seedstock ranch and diversified farm just north of Woodbine, Kan., about 30 minutes south of Junction City on the edge of the Kansas Flint Hills. Rock Springs Ranch State 4-H Center was in her family’s backyard.

While at Kansas State University, Jennifer was a member of the Sigma Kappa Sorority and a national officer for the Agricultural Communicators of Tomorrow. She graduated in May 2000 with a bachelor’s degree in agricultural communications and a minor in animal science. In August 2000 Jennifer started her 20-year agricultural writing career in Dodge City, Kan., on the far southwest corner of the state.

She’s traveled across the U.S. writing on wheat, sorghum, corn, cotton, dairy and beef stories as well as breaking news and policy at the local, state and national levels. Latzke has traveled across Mexico and South America with the U.S. Wheat Associates and toured Vietnam as a member of KARL Class X. She’s traveled to Argentina as one of 10 IFAJ-Alltech Young Leaders in Agricultural Journalism. And she was part of a delegation of AAEA: The Ag Communicators Network members invited to Cuba.

Jennifer’s an award-winning writer, columnist, and podcaster, recognized by the Kansas Professional Communicators, Kansas Press Association, the National Federation of Presswomen, Livestock Publications Council, and AAEA. In 2019, Jennifer reached the pinnacle of achievements, earning the title of “Writer of Merit” from AAEA.

Trips and accolades are lovely, but Jennifer says she is happiest on the road talking to farmers and ranchers and gathering stories and photos to share with readers.

“It’s an honor and a great responsibility to be able to tell someone’s story and bring them recognition for their work on the land,” Jennifer says. “But my role is also evolving to help our more urban neighbors understand the issues our Kansas farmers face in bringing the food and fiber to their store shelves.”

She spends her time gardening, crafting, watching K-State football, and cheering on her nephews and niece in their 4-H projects. She can be found on Twitter at @Latzke.

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