By: Mike Toohill

Bloomington, IL

It’s only May 3rd as I type but last night’s tenth looks like an inch in the fields close to our Bloomington, Illinois house. There is still some water in the ponds locally and the 7-day forecast continues the wet weather. Thus, some quick thoughts on my decades of dealing with planting delays are in order on this damp day.

What does the data say? The latest planting date study from Illinois farmdoc (2022) that I could find is below although I’m sure an update will coming if the rains continue.

The numbers suggest (and my experiences over the years back this up) that around a May 10th planting date is when it gets much more difficult to achieve maximum yield for both corn and soybeans granting that maximum yields are still obtainable (especially for corn).

I get more concerned as planting dates approach May 20th. At that time, we will get little soybean growth before the summer solstice and corn pollination will be pushed back until mid-July occur when temperatures are historically the hottest. Grower/agronomist concern becomes much higher when the planter/s are still parked heading towards Memorial Day weekend.

Some management thoughts as May slips away….

What about soil conditions at planting? Ideally, we will get a good window and growers can start on the driest fields and over time the wetter one will have good soil conditions by the time the planter gets there. This approach is best to limit the soil compaction that almost always accompanies planting delays. But in most years with May and June delays, the window is tight with more rain in the forecast. In that case every farmer has to make the decision on how much wetter soil he is willing to plant (90% good and 10% heavy for example?) in order to get the crop in before the next rain. I wish I had the “magic” answer on this topic but I don’t.
Closely monitor planting depth on those hot windy days with less than perfect soil conditions. Temperatures are almost warmer in mid-May into June than our preferred April planting dates. Thus, one needs to make sure all the seed is in good moisture on those rushed days when very minute is valuable. Heavy soils are also more prone to work up chunky behind the tillage tool adding to proper moisture at seed depth challenges. Open seed trenches are also much more common in damp no till situations. Over the years I have walked hundreds of corn and bean fields that were planted too shallow and/or with exposed seed on a hot day when the 70% chance of rain turned into 7 drops. Not much to do in these situations but wait for a rain (in non-irrigated situations) and accept the yield loss.
Strongly consider a comprehensive wind policy (if you don’t already have one) with mid-May and later planted corn fields. Late planted corn almost always grows very fast and green snap risk is high through and a little after pollination. Taller than the combine corn is also very prone to root lodging all season long.

Hang in there if you are experiencing planting delays! As always feel free to call or text at 217-369-6646. If you call, please leave a voicemail and I’ll get back to you as quick as I can.