Corn root system development
We routinely harvest only a fraction of the genetic potential our crops are capable of. Few of us actually know what a really healthy crop actually looks like anymore. Here is an image that describes what is possible.
This is a photo of corn root system from Al Trouse, from a demonstration conducted at the National Soil Laboratory at Auburn University.
The photo and notes below were shared by Jim Martindale from Cursebuster, who heard Al Trouse’s presentation to a group of Brookside consultants approximately 1979 or 1980.
In this demonstration, soil was sifted into a growth chamber so it would have a uniform density (other than gravitational pull). In this growth chamber with uniform soil density, the seminal roots reached the bottom of the chamber (6+ feet) in a few days.
Growing roots extend very rapidly though the soil until they encounter any change in soil density. When they encounter either an increase or decrease in soil density, they temporarily stop extending, and then slowly begin growing once more. If the soil density is uniform, they will extend very rapidly during the root systems establishment phase. Each growing root tip will extend for 72 hours, and stop growing after that period. The rapidly growing tips grew to the bottom of the growth chamber in 72 hours or less.
During the establishment phase, plants expand their seminal root system as widely and deeply as possible. This phase lasts for about 40 days, until the ear embryo begins to form. The outer root system boundaries are established during this phase. Future root growth does not expand past the established borders. What might this mean for cultivation close to the 40 day mark? Disturbing root systems at this point doesn’t seem like a wise idea.
Once the embryo begins to form, the root system shifts to the expansion phase, where fine roots emanate from the seminal root mass that has already been established, and fill the zone inside the established boundaries. This root system expansion period lasts until pollen drop. After the plant has dropped pollen, no additional root system development takes place.
The normal precipitation rate for Auburn University for the growing season was added with no fertilization.
Yields were estimated at 400 bushel per acre at normal plant density.
Each of the large blocks in the photo below ris 12 inches, total depth from the surface is 78 inches.
We have lots of upward potential left. I have never seen a corn plant in the field with a comparable root system.