Closing Wheels – The Studies

You’ve probably noticed that the farm magazines sometimes publish summaries or studies of closing wheel comparisons, and other vendors like to tout whichever study shows their brand(s) or style(s) of closing wheels comparing favorably. You might also have noticed that our Thompson wheels often aren’t mentioned. Why?
Sometimes these studies are conducted, and we’re simply not invited. Guess we’re too quiet. 😄 Other companies certainly spend far more to promote their closing wheels in the various publications, and/or dealer networks. We prefer to not need to mark up our products so much to pay for all that advertising and dealerships. And our best marketing has always been the farmers who are overwhelmingly happy with our products—we prefer to take some of those advertising and dealership dollars and instead invest that into research to make sure we offer only the very best.

In other studies, we’ve been invited to supply Thompson wheels (and toe-out wedges) to be included, but sometimes we decline because the people conducting the trial won’t agree to use Mojo Wires on the Keetons or Flo-Rites. Because the Thompson wheels do almost zero packing of the soil above the seed (which is a good thing, so long as you’ve done adequate seed firming at the seed’s location—packing above the seed only slows germination and emergence, impedes root growth, and leads to crusting and thinner stands), we’re completely reliant on the Keeton or Flo-Rite for seed-to-soil contact and uniform germination. And we know from third-party studies that Mojos provide advantages over a naked Keeton even in the mellow soils of the Corn Belt.

So, while you might not see Thompson wheels included in studies or lots of splashy advertising of them, we’re still confident they’re the best out there for the majority of conditions, wet or dry, high clay or loamy (we conduct our own studies every year, and if we could find something better, we’d be selling it). And they’re built to last!

While we can appreciate you wanting definitive, clear-cut, hard evidence that whichever closing wheel is “the best,” I’d like to emphasize that results do jump around a bit from year to year (we do very meticulous trials every year, analyzing early growth uniformity of the plants down a few hundred feet of row—it’s painstaking). The best closing configuration one year might not be the best the following year—slightly wetter or drier, different soil texture, different soil OM, etc. That said, there’s usually just a couple setups that are consistently near the top, and Thompsons with 3-degrees of toe-out and light spring pressure are one of those combinations (we test all other closing systems with Keetons + Mojos, not just our Thompson wheels).
By all means, do your own testing. But please, for your own sake, do it at least 2 years before reaching major conclusions. And pay attention to the details—what might seem like trivial differences in how far apart the wheels are spaced, or what spring pressure is being ran, will often dictate the outcome. Any given type of spoked closing wheel can be made to perform poorly. And watch out for bent closing brackets or row units—even the cast ones can bend (if you’re looking at more than 1 row of any given setup, then this eliminates much of this concern). I would suggest not only doing stand counts (not including any late-emerging plants, however) but also studying root growth when the corn is 18” or so. And, harvest those rows separately—but do the stand counts so you know if what you’re seeing is a population effect, or is mostly related to uniformity of emergence and/or improved rooting.

For more information on how the various closing wheel types behave in various scenarios, visit our website.