The fact that you completed planting so early last year in many cases is adding stress when you haven't been able to complete planting in one fell swoop as quick as you want to this spring.
It's possible that early planting last year has exacerbated concerns about late planting this year. But Justin Petrosino, agronomist with Stewart Seeds, Greensburg, says it would be wise to forget about last year. It was off-the-charts in many ways, he says. This year is more like many springs you have faced vs. last year. So if planting progress is behind last season, don't panic.
One way you could panic is to switch hybrids and varieties. That one has already been discussed here – with specialists saying not to think about switching corn hybrids until Memorial Day at the earliest, unless you were going with a full-season hybrid and you get pushed back another The same holds for soybeans all the way into mid-June.
The other thing you might think you need to do is change populations. However, for corn, Petrosino advises staying with the population you intended to plant to Memorial Day. He sees no reason to adjust it.
The only time you may need to adjust corn seeding rates is if the planting season drags on, and you do switch hybrids later. Then you will need to reevaluate the proper planting rates for that hybrid on your farm in the fields where you will plant it.
The agronomist says that if first-crop soybean planting gets pushed back into June, you may want to consider increasing seeding rate. However, remember that work by Shaun Casteel at Purdue University indicates most people have been planting soybeans thicker than they need to anyway.
The problem with planting soybeans late, especially if it's into stressed conditions, Petrosino says, is that the plants may not produce as many pods or beans per pod. To compensate you may need to up the seeding rate. Depending on where you were with your original rate, you may need to up it by one-third for soybeans planted in June.