Is your planter still in the shed? Or if it's in the shop, have you been through it yet? Have you taken the units to a dealer with a metering stand to check individual row units, either finger pick-up or vacuum style? Did you take samples of the grades of seed you will be planting with you so that the dealer could calibrate it for you? Have you measured the size of seed disks to see if there's enough disc blade remaining to make as true of a vee-shape as possible instead of a w-shape?
Until you've done these things, Dave Nanda doesn't consider your planter ready to go if you're after top corn yields. Nanda is a plant breeder and crops consultant based in Indianapolis, Ind. Spending time on getting the planter ready may seem bothersome, especially since there may be more field work to do than normal this spring after a wet fall that left ruts behind with little tillage work done. But Nanda is confident nothing else you can do will return more payback on the time and money invested than having the planter in top condition.
He makes a habit of studying plant placement within fields when he travels during the summer. He identifies fields where placement is very good. When he checks back in the fall, yields are usually top-notch as well. And more times than not, whoever got the planter ready for the field and ran it while planting corn turns out to be a top-flight operator as well.
Bob Nielsen, a Purdue University Extension corn specialist, demonstrated through research studies several years ago that proper placement, both distance between plants and consistent seeding dept at planting time, can influence corn yields. The effect for proper placement can be as much as 3 to 5% difference in yield, with the more evenly spaced fields yielding more. At today's yield levels, even on an average field, that can amount to 5 to 8 bushels of corn per acre.
It makes sense that more evenly spaced stands would perform better, Nanda believes. As soon as plants emerge, they can sense competition around them. The competition can come from weeds or other plants. If a plant is too close, say because the planter dropped doubles or even triples, it will likely cause the plant early in the growing season to decide it can't make as big of an ear. At that stage the determination may cause it to elect to design an ear with fewer rows of kernels around the ear than if it was in an ideal situation.
Uneven depth placement is a big issue in no-till, notes Barry Fisher, state agronomist for the Natural Resource Conservation Service in Indiana. It's important in any system, but in no-till soil temperature can vary more per half-inch than in conventional systems. Seeds that are planted deeper into cooler soil will likely be slower in emerging. If plants emerge more than a day or so late, next to plants that emerge on time, they may wind up either being barren stalks or putting on nubbin-type ears. Even emergence resulting from consistent depth placement of seed while planting corn is also extremely important, Fisher concludes.