On yield differences - like Dennis I doubt there would be much if any measureable differences between them.

however there is a BIG difference in residue flow between 22" and 20" rows if you are in any sort of less than full tillage.

If we take the typical planter row unit it has two 4" wide gage wheels with another 2" between them at the front of the vee opener and maybe 4" at the rear of the vee opener.

At the rear of the gage wheels then the overall width of the planter row unit is about 12".

At the tightest point between row units then on 20" row spacing there is about (20-12=) 8" between row units. On 22" row spacing there is about (22-12=)  10" between row units for residue to flow.

22" row spacing therefore has about 25% more room between the row units for residue flow than 20" row spacing. In many cases this is very significant as far as the ability of the planter to flow residue between rows without plugging. jmho.

Jim at Dawn