Dry, warm fall brings fertilizer reminders

WATERMAN, Ill. — While the extended dry, warm fall has made harvest of corn and soybeans smoother for farmers, it also means farmers might have to put the brakes on when it comes to fall fertilizer applications.

“For the most part, they’re happy with the warm, mild temperatures. It’s made it pretty comfortable to be out there,” said Jim Donnelly, technical agronomist with DEKALB brand corn and Asgrow brand soybeans, based in northern Illinois.

The 4R Nutrient Stewardship framework — which provides guidelines on the right source, right rate, right placement and right time for farm nutrient applications — advises waiting to apply fall nitrogen until maximum daily soil temperatures at the 4-inch level fall to 50 degrees and temperatures are forecast to steadily decline.

“The biggest thing is nutrient application. Ammonia applications are first and foremost the biggest concern that we have, as far as not putting nitrogen out there too soon because the soil temperatures are still so warm,” Donnelly said.

The dryness of soils also can impact fall nitrogen applications.

“From a dryness standpoint, make sure we’re not putting ammonia in dry soils as that will lead to unstable nitrogen, as well,” Donnelly said.

For farmers applying fall nitrogen, a nitrogen stabilizer is recommended.

“With as warm as it’s been, we 100% recommend stabilizer on ammonia and, frankly, we encourage stabilizers for any fall application,” the agronomist said.

Donnelly also added a caution for those farmers who plan to do soil tests.

“Most agronomists will recommend semi-frequent soil testing, usually once every four years. Sampling in the fall can sometimes lead to misleading results when you have a dry fall. Extremely dry soils can lead to erroneous potassium levels and sometimes pH levels,” he said.

“I urge caution when interpreting some of those results when they are taken under dry conditions. Potassium is one in particular that can show much lower levels than what is actually present, just due to soil moisture, or lack thereof.”

Overall, fall harvest in northern Illinois has been helped by extended warm and dry weather, which helped farmers in the field and at the grain dryer.

“It has been incredibly less stressful because of a seemingly and what has ended up to be a wide open calendar. There were just no hints of rain on the horizon and no need to rush,” Donnelly said.

“The corn was very dry and it’s just so much easier to handle that volume when it’s so dry. We can debate whether it’s a good thing to have corn that dry or not from a yield standpoint, but logistically it sure did make things quite a bit easier.”

He said substantial yields on corn helped to ease a little of the anxiety that farmers had going into the 2024 harvest.

“I think we went into harvest a little anxious just from a financial situation. Not that we still aren’t, but the yields have certainly helped ease some of that anxiety — and that’s a positive,” he said.