Some missteps on the farm are bigger than others. A bad decision with nitrogen (N) won’t just cost you yield; it will cost you cold, hard cash. Farm Journal Associate Field Agronomist Missy Bauer says maximizing N means being consistent all year long.
Pre-Emergence Applications
You must have enough N on the front end of the season, Bauer says. “In the early season, you’ve got to have enough N to help break down that previous crop’s residue and keep plants fed.”
Bauer often recommends a broadcast application of ammonium sulfate in either the spring or fall.
“A lack of sulfur in fields has gotten so much worse than in the past,” she says. “That application gives us some extra sulfur as well.”
Also, you can apply 28% or 32% UAN with a pre-emerge herbicide.
Aboard the Planter
Once the planter starts to roll, make sure a pop-up and/or a banded strip of starter fertilizer is available for early root development in corn.
“I like to see a relay effect,” Bauer explains. “If I have a little bit of pop-up or in-furrow fertilizer I can combine with a higher rate method such as the traditional two-by-two type band with N, then that really helps pay the carbon penalty.”
Adding 30 lb. to 35 lb. of N with the planter, in a band safely away from the seed, should get corn off to a good start, Bauer says.
In-Season Applications
Regardless of application method, plants normally need an in-season dose of N, Bauer says.
“A large portion of the nitrogen a corn plant is going to take up is during that V8 stage in to the tassel stage,” she says. “The plant is looking for 7 lb. to 8 lb. of N per acre per day during that period. So, you need to make sure the majority of N is available before then.”
After tassel, N applications make sure plants have enough horsepower to maximize kernel depth.
Weatherproof Your Nitrogen
Weather issues exacerbated by poor tillage, compaction or planting problems can cause issues with N uptake. Farm Journal Associate Field Agronomist Missy Bauer recommends farmers walk their fields and dig into areas where N seems to be in short supply. She says it’s not uncommon fields with the same management to show differing signs of stress. The goal is to find out why. “I encourage people to do some tissue testing in corn,” Bauer says. “Get about 15 ear leaves around tassel, put them in a paper bag and then send them in for a tissue test.”
