Enough in-field trials are in the books that you can count on uniform emergence vs. emergence issues being worth 5% to 9% more corn yield.
“We start there and figure out what steps you can take so that you can capture uniform emergence and maximize yield potential,” says Jason Kienast, a Pioneer field agronomist in southwest Iowa.
Kienast can’t guarantee picket fence stands, with all plants emerging within 12 to 24 hours of each other. But following these tips can give your fields an edge when it comes to achieving uniform emergence:
Level the planter. Take a level and place it on the planter frame, Kienast says. “You will be surprised what a tiny shim tucked under the planter tongue on the drawbar can contribute toward reaching yield potential if it’s what makes the planter run level with the soil surface,” he says.
Why? If the planter tips forward, you may set a false seed trench bottom with residue wheels rather than disc openers, he explains. That can result in air pockets, which aren’t conducive to even germination and emergence.
Check depth placement on each row unit. Even new planters may place seed at different depths row to row, despite being set at the exact same row settings. Check actual depth on each row before you go to the field, Kienast recommends.
Use 2-by-4-inch boards, one placed under the gauge wheels on each side of the row, to hold up gauge wheels and let disc openers fall lower. Notice where the T-handle should be set on each row so you can achieve the same seed depth across the planter.
Flag plants as they emerge. Use different-colored flags for plants that emerge later. It won’t help this year’s stand, but it will help you better analyze planter performance. If something about the planter pass is causing emergence issues, the time to address it for next season is right after planting, not next winter. It’s tougher to document that you have a problem unless you observe closely. Flagging helps you pay attention and document performance.
Deal with downforce. Anecdotal data indicates that over half of the planters in service are equipped with either springs or pneumatic downforce systems.
“You can do a good job with these in many cases, if you take time to set them correctly,” Kienast says. “What you can’t do, however, is account for row-to-row variation in conditions rows will encounter across the planter pass.”
That’s why Kienast sees value in hydraulic downforce systems that allow you to adjust row by row.
“Just make sure the system you’re getting, if you’re switching now, also allows you to apply from zero to 50 pounds of upforce,” he suggests. “Just in one pass, you could encounter places where tires ran where more down pressure is needed versus mellow soil where you may need upforce. There can be tremendous variation across one planter pass with a large planter.”