You say all row widths are equal with a little going toward 7.5 on the yeild side.
Well if the 30's are planted less population and less seed cost is not the advantage back to the 30's on profit?
I mine if you plant 180,000 drilled and 130,000 or less on 30's the 30's should have the advantage.
Would like to know what you planted at in each row width.