Here are as couple pictures shared by an Iowa Pluribus strip till customer who puts about 1/3 of his N down as dry Urea with a Montag cart in the spring strip just ahead of the planter then side dresses about 2/3 of his N (the rest of it!) on 60" centers as NH3.

I think it is safe to say that there does not appear to be any yield drag in this customer's system! It's not exactly what you are doing (1/3 N in spring strip just ahead of the planter) but the 60" side dress must work well (=no yield drag) or this very meticulous customer would be using 30". The 60" does cut down on the knife hp required and lets this compaction minded customer get by with singles on 120" centers and little or no weights.

I'll post a picture of his 60" knife rig also. (thanks to this E IA customer for sharing his pictures). Please pardon the overlays, these are the only copies of these photos I have available right now.

Jim at Dawn

(Dawn Striptill Corn on Corn IA sidedress bar for 60 ctrs jun 05.JPG)

(Dawn Striptill Corn on Corn IA sidedressed on 60 ctrs hp0155 jun 05.jpg)

(Dawn Striptill Corn on Corn E IA 7-25-05 hp175 cust photo -last yr residue + spring cleared strip.jpg)

(Dawn Striptill Corn on Corn E IA 7-25-05 hp178 cust photo corn field uniformity.jpg)

Dawn Striptill Corn on Corn IA sidedress bar for 60 ctrs jun 05.JPG (46KB - 119 downloads)

Dawn Striptill Corn on Corn IA sidedressed on 60 ctrs hp0155 jun 05.jpg (91KB - 93 downloads)

Dawn Striptill Corn on Corn E IA 7-25-05 hp175 cust photo -last yr residue + spring cleared strip.jpg (81KB - 108 downloads)

Dawn Striptill Corn on Corn E IA 7-25-05 hp178 cust photo corn field uniformity.jpg (56KB - 88 downloads)