One thing Clint Arnholt doesn't do is stick with the norm. If he can find a better or more economical way to do it, he will.
Arnholt, Columbus, is one of apparently a minority of farmers so far who have figured out how to adapt high-clearance sprayers to seed cover crops into standing crops in the fall. He removed the spray tank and mounted a seeder on his sprayer. Arnholt seeded a large number of acres to cover crops last fall. He's also looking to seed cover crops as custom work for people who want them seeded.
According to a survey of 70 Indiana Prairie Farmer Master Farmers, Arnholt is still in the minority. Only one Master Farmer said he had converted a high-clearance rig and was seeding into standing crops to get a jump for the cover crop before corn or soybeans were harvested.
The rest of the respondents were split between three application methods. Nearly one-third who grow cover crops have the seed applied aerially into standing crops. Another one-third broadcast the seed after harvest. This may or may not include some form of incorporating the seed into the soil. Another one-third wait until after harvest and drill the cover crop.
Aerial application is faster, but some worry about getting the necessary rain after application to get the seed started. This could also be true of high-clearance, surface applications. Others report less than acceptable success with uniform stands, with some strips sown aerially being lush and then some spots missed altogether.
The knock on waiting until after harvest is unless you have an early soybean, it could be pushing the late side of the planting date for some cover crops. Annual ryegrass is one that benefits from fairly early seeding in the fall. The same could be said for drilling. What people who drill report is that they get the seed covered and plant into a better seedbed. Since rye can be planted later than many of the other cover crops, it's a good choice if you're going to drill after harvest.