A wet spring and dry summer make for wild yield swings
A wet spring and dry summer make for wild yield swings
Most of the regions in Kentucky growing corn and soybeans received between 40 to 51 inches of rain by the first week of July. Most of those same regions have received very little or scattered rains since. The timing of when corn and soybeans were planted and when they are scheduled to mature will make for some wild yield swings in 2025.
Corn
Corn planted on time in the western regions of Kentucky is being harvested now. Reports are coming in of excellent to phenomenal yields in some of those fields. Corn in those fields had plenty of water in the soil to complete seed fill. The dry weather during the latter phases of seed fill helped keep diseases away and allowed for rapid drydown after that corn reached blacklayer. The combination of favorable moisture for seed fill and dry weather during kernel drydown often favors better grain quality.
Corn planted a few weeks or a month later has had a more difficult challenge. Most of that corn made it through pollination with little issues. But, the dry weather through seed set and seed fill reduced kernel number and is likely reducing kernel weight. Kernel drydown after blacklayer should be rapid, but yields are likely to be below five-year averages. Normally, we might expect these conditions to lower test weights. But, for some fields the dry weather was so long that test weight may be just fine even if yields are off target.
Corn planted into wet conditions that resulted in sidewall compaction or subsurface compaction have run out of water prematurely and yields will be lower. Yields will be much lower in some of those fields.
On a very general observation, corn west of Leitchfield and south of Horse Cave that was planted on time and into good conditions should have good to excellent yields. Corn from about Leitchfield eastward was planted later due to heavy rains and experienced more severe drought conditions during seed fill. Yields are likely to be less overall in these areas. However, there are pockets in this region where corn yields will be excellent.
Soybeans
This year, full-season soybeans are likely to fair much better than double-crop soybeans…unless those double-crop soybeans get some timely, frequent gentle rains the next two weeks. In the Bluegrass Region, I have watched a soybean field on an eroded slope go backwards for the last three weeks until 80% of the plants passed the wilting point in the field. This is the extreme case and is repeated in small areas of fields around the state.
Soybeans have a better chance to escape short periods of stress because they have multiple locations on a plant to develop flowers, pods and seeds. In September, there are very little opportunities for soybeans to add more pods to plants … unless we have an unusually warm September, timely rainfalls and a late frost.
For many full season soybean fields, I am expecting to see decent seed numbers but smaller seed sizes. For double-crop fields, I am expecting to see lower seed number and lower seed size, resulting in lower yields.
This dry weather will identify all the thin soils in a field. Those soybeans will shut down faster than soybeans in the better areas. Aerial photos of fields taken as the soybeans in the thin soils mature faster could be compared with soils maps and previous yield maps to help confirm precision management strategies.
Timing is Critical
Once again, this year reminds all of us how important timing of rainfall is. Even though our annual rainfall totals will be above normal, many of the corn and soybean fields had less than average rainfall totals when water was needed the most. That timing will be the biggest difference between a crop success and a crop disappointment this year.
Thank you to Clint Hardy, Katie Hughes, Nick Roy, Vicki Shadrick, and Tom Miller, County Agriculture and Natural Resources Extension Agents, for their comments and observations.
| Citation: Lee, C., 2025. A Wet Spring and Dry Summer Make for Wild Yield Swings. Kentucky Field Crops News, Vol 1, Issue 9. University of Kentucky, September 12, 2025. |
