Root growth is a gravitropic response, i.e., roots naturally develop downward in response to gravity as long as conditions are conducive for continued development. Conducive conditions are primarily adequate moisture and temperature but also obviously include soil tilth. Generally, wet soils early in the season result in shallower rooting primarily because wet soils warm more slowly. If upper soil layers warm slowly, deeper soil layers warm even more slowly (less heat conductance). If deeper soil temperatures are limiting (i.e., less than 50 degrees F), roots will tend to proliferate in the warmer, upper soil layers. Conversely, drier than normal periods following corn planting tend to encourage deeper rooting because the deeper soil layers warm more quickly. Roots do not grow toward water. They proliferate where conditions are conducive.

For more information on this and other topics related to corn production, contact your state extension corn specialist or your local extension educator/agent.

Following is the link to the corn extension specialists: state extension corn specialist.