It’s been said that every day after you plant your corn, the yield potential goes down. The weather isn’t perfect. You don’t get enough sun. You don’t get enough rain. Your soil isn’t perfectly providing nutrients, etc. The key to actually keeping the majority of your yield potential (which is well over 1000 bushels per acre by the way) is to do everything you can control just right. It starts with planting your seed corn at the right depth.

Corn needs to be planted at least an inch and a half deep but no deeper than two and a half inches. When you get too deep, it takes too much energy for that tiny corn plant to get out of the ground. Surface crusting is an issue. Insects getting to the plant before it can emerge can be a problem. Cold soil temps could be an issue. There are a lot of things that can go wrong if you’re planting three or four inches deep, but planting too shallow may be an even bigger concern.

As a corn plant germinates, it sends out a root to anchor the plant and begin the process of bringing in water and nutrients. At nearly the same time, the corn plant sends a shoot up towards the surface to begin the process of growing the above ground portion of the plant. That shoot is called the hypocotyl. The hypocotyl is pushed up by the mesocotyl. The mesocotyl is always at least three quarters of an inch long. On top of the mesocotyl, five rings of nodal roots will develop. The nodal roots are the main system for nutrient gathering and water intake. They will need at least three quarters of an inch to develop. Again, the mesocotyl will be at least 3/4” and the nodal rings will develop in at least 3/4”, so added together, that’s 1.5 inches minimum planting depth.

If corn is planted too shallow, the result will be roots above ground rather than below ground. Here are the problems with that: the plant won’t be anchored well, so lodging will be more of an issue than normal; if nodal roots are exposed, they
cannot bring in as much water or nutrients; if nodal roots are exposed, your plant is more likely to experience chemical damage, insect feeding, and disease infection. Most importantly, if you plant your corn at less than 1.5 inches deep, there’s a 100% chance you’ve lost yield.

In summary, don’t ever plant your corn deeper than 2.5 inches deep or no less than 1.5 inches deep. Your best bet is to set your planter for a two inch planting depth,
regardless of weather or soil conditions. Just keep in mind that if you have compacted fields, your depth is not going to be the same as fields that may be soft. Get out of the tractor and check the planting depth as often as possible. Especially when soil conditions change, checking and adjusting the planting depth is critical.

Plant your corn 1.5 to 2.5 inches deep to maximize your yield potential this year.