A firm seedbed at planting is critical for good seed-to-soil contact and establishment of the nodal roots which develop near the soil surface. A seedbed can be considered too loose if one sinks greater than one inch when walking through the field, but this can vary with planting equipment. At the same time, avoid excessive pre-plant tillage, which can result in surface crusting and emergence problems if heavy rainfall occurs prior to emergence. Excessive pre-plant tillage also enhances the risk of wind erosion and sandblasting to corn seedlings.
A planting depth of 2 inches is optimal for corn in most situations in Minnesota. Shallow placement of seed increases the risk of poor nodal root establishment. High planting speeds that result in bounce of planter units should be avoided, as this can result in shallow placement of some seeds and variable emergence