Pat O’Conner, owner of O’Connor Family Farms in Blooming Prairie, Minn., headed out to plant corn around 5 p.m. Friday when he realized his planter’s precision guidance system wasn’t working properly. He tinkered with it for a while before calling his local dealer for help.

“They had recorded a voicemail that said: ‘It’s Friday, May 10. There’s a huge solar flare-up that will likely be affecting the GPS signal tonight,’” O’Connor recalls. “I shut down for the evening. We were close enough to being done with planting that it wasn’t a huge time crunch. I shut down and prepared another field for the rest of the day.”

Technology run amok

If, like O’Connor, your GPS suddenly went squirrelly this weekend, you weren’t alone. The intense solar storm that launched charged particles into the Earth’s upper atmosphere beginning Friday — illuminating much of the northern United States in mesmerizing aurora light — disrupted precise point positioning systems, reducing GPS accuracy on farm equipment. The storm also impacted broadband, and radio and satellite communications.

The disruption of point positioning systems like RTK — which triangulate centimeter-level location data using global navigation satellite systems, terrestrial base stations and machine-mounted receivers —rendered some precision planting equipment ineffective.

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Specifically, base stations were sending false navigational corrections to machines because of the geomagnetic interference. The storm, which was the strongest to reach Earth since 2003, has been downgraded by the National Oceanic and Atmospheric Administration. Even so, its effects could linger for farmers.

Planter performance under scrutiny

“We strongly advise you to keep an eye on your guess rows,” the space between planter passes, reads an alert sent to customers by LandMark Implement, a John Deere dealership with a footprint across Nebraska and northern Kansas.

Dealers everywhere were inundated with inquiries during the event. “We experienced a pass where the guess row was 10 inches wide, and the receiver was showing a PDOP value of 1.1, which would typically mean good accuracy,” or the strength of the current satellite. “This can also affect your section control, but we don’t expect it to create any excessively large overlaps or skips.”

TEMPORARY SETBACK: “I shut down for the evening. We were close enough to being done with planting that it wasn’t a huge time crunch,” says Pat O’Connor, pictured with his soybean planter. (Pat O’Connor)

Alerts published ahead of the solar event prompted many farmers like O’Connor to pause planting. Some retrieved legacy planters with mechanical row markers from the back of the shed.

Others, like Nebraska farmer Dexter Griebel, planted through the disruption using modern equipment. Griebel says his machine’s RTK system stopped working altogether. When that happened, he switched to John Deere’s SF1 satellite-based correction signal that has a pass-to-pass accuracy of ±6 inches.

“The rows that are off won’t impact me that much — other than the neighbors giving me crap for having ‘sloppy rows,’” he quips. “The only side effect is that some guess rows are wide, and some are narrow. The RTK was off 6 to 15 inches in some places.”

The disruption hasn’t shaken Griebel’s reliance on precision technology. “GPS guidance, in my opinion, is one of the best things to ever happen to farming. I will continue to use it regardless of issues like solar storms,” he says.

For those who planted over the weekend, LandMark Implement’s alert advises checking planting row accuracy when heading back into the field to sidedress, spray, cultivate and harvest in the coming months.

“We expect that the rows won’t be where the AutoPath lines think they are,” the alert states. “This will only affect the fields that are planted during times of reduced accuracy. It is most likely going to be difficult — if not impossible — to make AutoPath work in these fields, as the inaccuracy is most likely inconsistent.”

The alert noted that while certain receivers were impacted worse than others, the solar storm affected all machinery brands that use precision guidance. Guidance systems that receive information from more satellite constellations were generally able to function better than those connected to fewer.

Storm-day decisions

“While weather and field conditions across North America had paused many operators in the field, producers who were able to run Friday and Saturday may have experienced unexpected accuracy changes while using autoguidance and other GPS-based features due to recent solar activity,” says Kendal Quandahl, manager of Case IH's precision field team, in an email.

Just like a rain event, the solar storm forced producers to decide if continuing to plant was prudent, knowing they may experience interruptions. “For those producers who opted to plant, utilizing a scouting app like AFS Connect can help map and mark areas to watch for reference on future passes,” she says.

Referencing GPS quality map layers with the emerging crop can direct a producer or field scout to pay extra attention to areas with potential skips and overlaps throughout the season, according to Quandahl. 

Affected areas may also not align to expected guidance lines when making season-long passes. Operators may need to remark or adjust guidance lines throughout the field to protect the crop, she says. 

Minor setback

In the grand scheme of things, O’Connor says the space storm won’t affect his yield this year.

The disruption came after two weeks of rain, which delayed planting. Even so, his pause was calculated. The field he was planting on has a drainage ditch cutting through it, and because of that, his planter requires GPS to avoid overlap and gaps, he wrote in a Facebook post. Without precision guidance, he would have had to abandon variable-rate seeding.

“I’m not willing to cut corners on our crops,” he says. “We take pride in managing every acre to the best of our abilities. Sometimes, that means being patient, regrouping and getting the job done right. I’m not farming to cover the acres as quickly as possible. I’m focused on quality.”

COLLIDING COLORS: The aurora borealis as seen over Lindstrom, Minn., last weekend. The solar storm brought with it beautiful lights and reduced GPS accuracy. (Jennifer Koukol)

But while it might not have been a big setback, the event serves to remind farmers of the far-reaching and sometimes unpredictable impact weather can have — not just on planting but also on the technology that helps improve planting accuracy and yield.

“It wasn’t the end of the world. But had it been the first part of the season, or if there was weather looming, I definitely would have had to figure out how to power through and keep going,” O’Connor concludes.