Several factors affect the choice of corn seeding depth. 

Although many areas have received late winter precipitation, dry soil is still a concern in areas where tillage allows significant surface drying or precipitation has not occurred.

Corn Seeding Depth:  Back to the Basics, a recent ICM News article, discusses how to select appropriate seed depth. This article focuses on planter adjustment settings and considerations if seed is planted deeper than normal due to dry conditions in the upper two inches at the surface.

Dry surface soil suggests deeper planting depths to obtain moisture for rapid germination. 

The seed depth adjustment on planters controls the distance between the bottom of the double-disc seed opener and bottom of depth-gauge wheels. 

Most planter row units have the ability to adjust this difference to at least 3 or 4 inches. Simply adjusting this depth difference between gauge wheels and seed opener, however, will not automatically mean seed is placed at the adjustment depth. 

A certain amount of weight or down force is required to push the seed opener into the soil before the adjacent depth wheel comes into contact with the surface. The down force required increases with increasing penetration depth. This is similar to increased force required to drive a spade deeper into the soil. 

It’s always a good idea to make sure depth-gauge wheels are in contact with the soil surface. This check is particularly necessary when planting at deeper than normal depths or if dry soil increases penetration resistance encountered by the seed opener. 

If gauge wheels are not on the soil surface, extra weight must be transferred to the row unit via the down force system on the parallel links attaching the row unit to the planter frame.