Production Blog

It's a white rabbit spring.

Remember the rabbit in Lewis Carroll's Alice's Adventures in Wonderland who had a preoccupation with time and being "late?" That's a common panic for farmers as April exits and May emerges.

This year, the angst seems a little more pronounced agreed Stephanie Porter, outreach agronomist with the Illinois Soybean Association. "There's a big push to plant early these days and maybe that's adding to the worry," said Porter, in an interview with DTN.

"But we're far from late. We have a few more weeks before that trend line of where we start losing bushels in this state," she added.

Porter is referring to University of Illinois optimum planting date numbers based on trial data. Data compiled from studies between 2007 and 2024 show that the optimal planting date for Illinois being between mid-to-late April. Yield declined gradually as planting is delayed, with corn planted in early May reaching 93% of maximum yields, further decreasing to 85% if planted in late May and 79% in early June.

A similar study for soybeans found those planted between mid-to-late April were within 2% of maximum yields. Soybeans planted in early May reaching 94% of maximum yields, which further drops to 88% by May 31, 80% by June 15, and 77% by June 20. As the planting date gets pushed further back, the soybean plant will develop fewer leaves, which further limits yield potential. Read more about the studies here https://extension.illinois.edu/…. Find charts by planting date here: https://extension.illinois.edu/….

Spotty weather conditions and forecasts for rain in early May add to mania, Porter agreed, noting that it's a rare season where there aren't some delays.

"Some farmers had perfect planting conditions in early March and planted some ultra-early beans. I think they all wondered if it was just too early, but those that got locked out most of April are glad they went ahead," she said.

Planting season typically lasts from six to eight weeks, no matter how fast we hurry, noted Mark Licht, Iowa State University cropping extension specialist in a recent release: (https://crops.extension.iastate.edu/…).

Iowa data from USDA National Agricultural Statistics Service (NASS) shows a shift to earlier planting and a move to plant soybeans earlier than corn. However, while planting may be earlier, planting completion is occurring only minimally earlier, Licht said.

Bigger equipment and the desire to cover more acres increases the total acres that might get planted in a day, but weather holds the cards, agreed Licht in an email to DTN.

"We know that spring weather has trended toward wetter springs (mostly higher intensity storms); however, the other trend of warmer springs leads to planting earlier. So, while we can start earlier and cover more ground faster, we also have potential for more weather delays," he said.

Checking in with farmers this week, Porter said she's been pleasantly surprised how many acres have been planted so far. If the calendar gets to mid-May, farmers may want to consider finishing up corn since its yields fall off faster than soybeans beyond the optimum planting window.

"I try to encourage people not to get too hung up on the calendar. A lot of other things go into final yield. Mother Nature holds the cards, no matter when we plant," she added.

Pamela Smith can be reached at pamela.smith@dtn.com

Follow her on social media platform X @PamSmithDTN

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