Scrutinize Your Stand

ROCKVILLE, Md. (DTN) -- It had been three weeks since planting, and Kyle Samp still had no sign of a corn crop.

The Moberly, Missouri farmer really couldn't blame the corn. After warm soils and a good 10-day forecast lured him into planting in the first few days of April, ever fickle Mother Nature changed her mind.

"By the time we had stopped planting, the forecast had changed, and it got cold," Samp recalled. "The week after we planted, we had 4.5 inches of cold rain." Then an April snow squall blew in, briefly blanketed his newly planted fields and temperatures plunged into the mid-20s two nights in a row.

Samp was ready to throw in the towel. "I mentally prepared myself for replanting it," he told DTN. "I'd even talked to my seed guy about what we would use to replant."

But Samp is a veteran farmer, with 18 crops under his belt, so he did his due diligence and scouted faithfully. The second week after planting, he dug up some seeds and found them to be nice and firm, which gave him hope. Then after the third week, on the night before his new seed was set to be replanted, he walked the fields one last time.

"I called my dad and said, 'I think we've got a stand out here!'" Samp recalled. "I've never had corn lay in the ground for three weeks and still be viable." In retrospect, the bitter cold probably saved his crop, he noted, by putting his corn seed in shutdown mode, rather than trying to fight through the conditions to emerge.

With USDA estimating 67% of the nation's corn crop planted as of Monday, but only 20% emerged, a lot of farmers are in Samp's boots right now. The April pivot in the Midwest toward cool and wet has stalled germination and emergence, and continued dryness in other places has done the same.

Near Wells, Minnesota, for example, Mark Nowak is watching warily as his corn and soybean seeds search for moisture in bone-dry soils. "This was my 48th crop I've planted -- this has been the driest start/conditions I've planted into," he told DTN in an email. Low temperatures have piled on, freezing some soybeans in his region, even as others can't find enough moisture to germinate.

"Looks like the old adage of 'Plant in the dust and bins will bust,' may turn out to be 'Plant in the dust (drought) and crops a bust,'" he said. "I'm not giving up hope yet for a good crop, but we need to get emergence up to a good stand, and then we can go for a bit waiting for rain."

Checking and assessing your seed viability and stand health is more important than ever this spring, noted Iowa State University Extension cropping systems specialist Mark Licht, in a recent university article. Assessing three primary issues -- plant population, emergence uniformity and plant spacing -- will give you the roadmap toward replanting or sitting tight and letting a crop carry on, Licht said.

PLANT POPULATION

Iowa State recommends sampling corn planting population multiple times across a field, with each sample representing roughly 1/1000th of an acre, based on row width. That means, in a 30-inch-wide row field, a sample would be 17 feet and 5 inches long.

Count the live plants, repeat several times, average the counts and multiply that average by 1,000 to get a rough estimate of your plant population. This Iowa State guide includes a chart helping you know just how big your sample should be depending on your row spacing: https://crops.extension.iastate.edu/…

Although soybeans are better able to compensate for low populations, stand counts matter there, too. Experts recommend a number of ways to take those counts, from measuring out 1/1000th of an acre, to taking plants-per-row-foot counts, to tossing out a hula hoop and counting the number of plants inside. Whatever method you use, do it at least five times across a field, says an Iowa State guide that lays out each method here: https://crops.extension.iastate.edu/…

WHAT EMERGED, WHAT DIDN'T AND WHY

In addition to the raw count of live plants, emergency uniformity and plant spacing are also important clues to a field's yield potential, Licht noted.

"Emergence uniformity is considered problematic if early versus late emerging plants are greater than two weeks apart for corn," he cautioned. "For soybean emergence, uniformity very rarely results in lost yield potential that warrants replanting. Like emergence uniformity, plant-to-plant spacing is more problematic for corn than soybean. However, if soybean has large gaps greater than 2 feet, this can be reason for concern."

When assessing emergence, remember that firm seed and plant tissue is the key to a living seedling. There are a number of things that could have stymied emerging seeds, including disease and insects, which often show up in brown, rotting seed and missing seed or half-eaten seedlings. And of course, your planter could be at fault, too -- improper seed depth, sidewall compaction, hairpinning and soil crusting can all thwart germination. This year, cold soils and the risk of imbibitional chilling could also have played a role. See more here: https://www.dtnpf.com/…

Herbicide carryover is a possible culprit this year, as well, especially in dry areas of the country. See more on that here from FS Companies: https://www.fssystem.com/…

THE REPLANT CALCULATION

Once, you have your stand counts and emergence variability in hand, it's time to make some tough decisions about replanting. It's one of Samp's least favorite parts of farming. "You don't want to give up on anything," he said. "I have some trusted people I turn to, to help me evaluate."

Various replant checklists compiled by industry and academics can also help you weigh your potential yield at current plant population, while keeping in mind emergence variability, estimated replant yield and replanting costs.

See a corn replant checklist from Iowa State here: https://crops.extension.iastate.edu/…

See a soybean replant checklist from University of Wisconsin Soybean Specialist Shawn Conley here: https://coolbean.info/…

Ultimately, Samp ended up replanting about 10% of his early-planted corn, in areas where plants per acre ranged from zero to 17,000.

"For me it was mostly about looking at the worst parts of the field and seeing what I had there," he explained. "If it was much less than a normal stand, it was a pretty easy decision."

See Iowa State's Licht's original article here: https://crops.extension.iastate.edu/…

Emily Unglesbee can be reached at: Emily.unglesbee@dtn.com

Follow her on Twitter @Emily_Unglesbee

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