I run a 19" row JD planter, in old No-till cornstalks, and it really isn't quite enough room, for trash to flow. This is with long parallel arms row units, between short parallel arms, plus using narrow gauge wheels(3" verses 4.5"), between rows. No way to use trash whippers on all rows = instant plugging(when damp); so had to just use No-till coulter on every other soybean row unit.(trash whippers on 38" corn rows, still)

Jim at Dawn, has mentioned that there was a big difference, in trash flow between 20" and 22".

He mentioned, you wouldn't think that extra 2" would be that much different, but it was. (with my experience, in 19" No-till, I would believe that statement, too)

Now, Last fall, I ran Calmers chopper corn head stalk rolls (littler pieces of stalks) and didn't have any plugging issues, This Spring; BUT I never tried ALL trash whippers, on each 19" row unit, either. (= may still have issues, with trash flow, trying row cleaners on ALL rows)

 Note: This is on sidehills, terraces and contours, where I can't seem to drive good enough to stay between old corn rootballs; so if you are on flat ground, your results would probably be better, if you didn't disturb old rootballs.

Now, if you get to close to a wet spot, and plug with mud; it sucks, to remove gauge wheels and clean out, that's for sure.

For maintenance, I use a creeper, on concrete to do some items, like changing seed tube guards (frogs), because you aren't going to get your body between units at 19".

Fred Below, thinks the future might be 20" rows(corn and beans), because most farmers will only want 1 planter to do both corn and beans.

If I had all sorts of money, it would be interesting to try a 20" or 22" rows on a 3 pt hitch planter, in these sidehills and contours conditions, for both No-till corn and beans, and see how well it works. Leave corn stalks as tall as possible, at Fall Harvest, and try and get soybeans right between old corn rows, the next Spring.(You don't see any 3 pt. planters around here)