By Darren Hefty

It’s no secret that even emergence leads to maximum yield potential in your corn fields.  It all starts with your planter.  One of the critical decisions you need to make is your target planting depth.  Then, you will need constant monitoring and attention to detail to make sure you execute this once-per-season opportunity.


Why is This a Big Deal?

When you think of any plant, it seems like common sense that you plant the seed and the roots go down, right?  However, with corn the main root system of the plant actually starts out ABOVE the seed.  For this reason, there is a minimum depth you need to plant your corn to avoid big problems.

Minimum Depth

You should never, ever plant more shallow than 1.5” deep.  The reason why is when corn germinates it sends up the mesocotyl, which is always at least 0.75” long.  Then the nodal roots form above that.  The five rings of nodal roots also need 0.75” to develop.  Add that up and you have the minimum planting depth of 1.5”.  Planting more shallow leads to roots above ground that are sensitive to harsh weather, herbicide injury, and insect feeding.  Plus, they won’t be able to take in nutrients or brace the plant as effectively if they are partially above ground.

Maximum Depth

We also don’t recommend planting deeper than 2.5”, as it requires too much energy for crop emergence.  If there is any degree of surface crusting or a high amount of plant material laying on the soil surface, you may see the corn plant start shooting up from the seed, only to turn around and head back down or just die trying to emerge.

Ideal Planting Depth

The window is 1.5” to 2.5” and the ideal planting depth is often right around 2”.  This gives you a cushion, as soil conditions will vary within a field and from field to field.  We added Precision Planting to our planter last year and saw a much more consistent planting depth due primarily to DeltaForce down pressure control.

There are many more things to watch out for in order to achieve and maintain a consistent planting depth.  Start with a target of 2” with your corn seed this year to get the best emergence, stand, and ultimately yield this season.