Paul,

It sounds like you have an interesting for comparison of different treatments on this 3rd year corn. I think a key to success on your no till is to get the 2-yr old residue out of the way. Sometimes this material is STILL firmly attached to a rootball in the ground. In no-till you will need to run the row cleaners aggressively enough to clear a path of most if not all 2 yr old corn residue to a black strip. You can leave the rootball but should clear the surface about 8" wide completely in my experience.

In my opinion row cleaners fixed (not floating) to the row unit are best in this condition. Floating works best in bean stubble in my opinion. Especially with depth bands, the floaters may tend to do just that - float up and over the still rooted stalks rather than clear them.

I think you will find strip till is really the way to do continuous corn, however depending on which type of machine you are using I would be very concerned about spring planting directly over a spring-made knife slot in many soils and moisture conditions. Knife slots really need the winter to sort of fill in all the way down and even then there are times where the slot is still open beneath the surface in some high clay soils.

The other poster mentions accelerated breakdown of stalks in continuous corn - it does take a few years of residue to get the soil life back up to their natural speed. They work as well and a lot cheaper than 28% over the top. jmho. Best of luck and please share your results.

Jim at Dawn