Closing wheels are considered key parts of the planter to maximize seed-to-soil contact which improves even emergence of corn and soybean seeds and maximize yields.

Closing wheels are designed to close the seed furrow and create an environment for even emergence. Jason Ward, North Carolina State University Extension precision ag specialist, says closing wheels perform an important role in efficient planting to improve yields.

“You have to establish good seed-to-soil contact, but not squeeze it so hard you create issues in emergence. To get timely and consistent emergence, we need to take a look at some of the tools we use to make sure we’re executing everything just right. We need to try to fix any issue that prevents that consistent emergence,” Ward said at the CHROME Regional Ag Expo at the Peanut Belt Research Station in Lewiston-Woodville, N.C.

There have been recent advances in closing wheel technologies with active sensing and automatic adjustments. While he believes in using the best technology that is profitable, Ward and his team have been demonstrating affordable closing wheel upgrades to see if there were differences among smooth, twister and metal tine closing wheels in both corn and soybean planting at the research station. 

Corn and soybeans were all planted the same with the only adjustment being a change to the closing wheel on the planter. Ward notes there wasn’t a huge difference among the different closing wheel systems.

This year, Ward and his team used a drone to do stand counts and emergence ratings in the corn site at the station. They conducted the first drone flight over the plot one week after planting, but no results were found because the corn plants were too small for the camera to see. But two weeks after planting, the drone was able to capture pictures of the emerging corn.

“Our populations, while not very different, were all averaging around 19,000 (plants) and 22,000 (plants)  on a target population of 27,000 (plants per acre). We actually had a pretty good gap in what we wanted that population to be two weeks after planting. Exactly 14 days after planting, we were leaving 5,000 seeds per acre un-emerged,” Ward said at the field day.

Ward stressed that just straight plant population may not be the right metric to maximize yields. Doing pin tests on freshly emerged plants and evaluating the different closing wheels is important. “The good news is this is something you can do yourself with relative ease and not a whole lot of cost. If you want to try tweaking something on your planter to get that optimum emergence, you can do that and it’s not hard to do.”

For soybeans, Ward and his team evaluated the same closing wheel systems on the planter. Ward noted that not a huge difference was seen in soybean plant populations two weeks after planting among the different closing wheels.

“We  did see with the smooth wheels that the variability was much higher. If you were using the stock wheels on soybeans this year, we saw a lot greater variability in stand counts. If you were using one of the after-market systems, you probably saw  more consistent emergence,” he explained.