Great Corn Harvest But Compaction Nipped Some Yields
Dr. Chad Lee
LEXINGTON, KY.
The corn yields being reported are excellent to date for Kentucky. With
the wet weather at planting, we all were very concerned about compaction
problems. The continued wet weather helped a lot of corn roots break
through compaction. We dodged a disaster, but corn yields were dinged by
the compaction. I walked a field yesterday where we think we may have
lost as much as 75 bushels per acre to compaction.
That’s the bad news. The good news is that the field went about 250
bushels per acre. That’s an excellent yield in most fields and
especially in a field with some compaction.
The roots overall in the field looked excellent and originally appeared
to have no compaction. Then, we found the ear on the right in the
picture. When we dug up that plant, the roots grew twice as deep as the
roots of the plant on the left. The majority of the corn in this field
looked like the ear on the left.
The ear on the left is on a plant withroots limited by compaction and the other is on a plant with no compaction.
Corn in this field was at a high population (43,000 plants per acre).
The ear on the right has about 160 more kernels. With the high
population and that many extra kernels, we get the 75 extra bushels.
There are two things to caution here: 1) When we simply compare these
two ears, we are assuming that if compaction had not been an issue, then
all ears would look like the one on the right; and 2) the field had
some perennial weeds that needed to be removed with tillage this spring.
That tillage led to the compaction. However, without controlling those
perennial weeds, this corn would never have gotten close to the 250
bushel mark.
Stephanie Halcomb holding a plant with no compaction. Yield potential was phenomenal this year.
So, these farmers did what they needed to do to remove the most limiting
factor: in this case, used tillage to remove weeds. But that tillage
this spring created some compaction. That compaction became the most
limiting factor. Perhaps, this serves as a good reminder that tillage
should only be done when absolutely necessary.∆
DR. CHAD LEE: Extension Agronomist, University of Kentucky