A number of years ago I remember reading about European farmers going to 4" or 6" wheat spacing to increase yields in their 100 bpa plus yield environment so I was always under the asumption that narrower was better. What I have found over the years is that in our yield environment I have not seen a yield penalty to rows up to 10" wide (have never planted anything wider). My brother has used a 10" dirll for many years and I used a 10" Hiniker air dirll for a number of years and I could never see a yield penalty and there are some advantages to wider rows - less openers to wear out and replace, more down pressure available per opener in no-till, less draft, more residue clearance, lower initial cost to name a few. One negative to wider rows could be more light penetration when the wheat is small so more weeds germinate.

I personally would not be afraid of a 10" drill, and it might have significant advantages if you were no-tilling with it concerning residue clearance and penetration in hard soil.

I think we can do a little better job of no-tilling double crop beans into wheat stubble with wider rows. The wheat root crowns are concentrated in a row with bare space between in drilled wheat - this additional bare space seems to be an advantage for getting beans covered with less hairpinning and the wider the wheat spacing the more bare space. I know the broadcast wheat seems to be the worst to no-till beans into as there is almost no bare ground - wheat root crowns everywhere.

A word of caution - they don't trade in well in our area, but then they don't cost as much to begin with either.

John