We see many folks in the northern 20" areas going back to 30" primarily for residue management reasons. There is just more room to clear a strip or path. The planters are also much easier and less costly to mount fertilizer coulters to, the planters and cornheads are much less costly and lighter, etc, etc. tougher to control traffic in 20" also. Basically life is just easier in corn on 30".

Residue management along with more corn and fewer beans at current prices tend to over shadow any minor yield or canopy differences. 30" lets you strip till. 20" strip till is a compromise if feasible at all.  jmho.

Jim at Dawn