When it comes to planting corn, how deep is deep enough and how shallow is too shallow? In a planting depth demonstration, DuPont Pioneer agronomy researchers evaluated how corn development is affected when planted at different depths. The results confirmed optimal planting depth in the Midwest is typically 1 ½ inches to 2 inches.
There are a number of reasons why growers may find varying planting depths within a single cornfield. These include planting at too high of speed, planting into heavy residue and planting in less than optimum soil conditions.
Corn planted too shallow may result in:
- Decreased ability to uptake water and nutrients through the roots
- Potential to develop “rootless corn syndrome” – causing plants to fall over due to the lack of nodal root development in dry soil
- Increased potential for herbicide injury due to exposure of corn seedlings to herbicide residues
To achieve optimum planting depth this spring, consider the following planting depth recommendations:
- Set the planting depth in the field, with the planter being pulled at full operating speed
- Check for good seed-soil contact
- Slower planting speeds achieve more uniform planting depths
- Utilize in-row residue management equipment when needed
- Utilize in-furrow seed depth control devices