In our area some fertilizer dealers have become successful at coulter injecting 28 or 32% UAN with some of the larger front-mount boom "high-boys", like the large Hagie or Miller Nitro. They can easily go thru corn 4-5' tall. The typical coulter injector you may see on a tool bar applicator is mounted to a long arm & suspended from the lift arms of the sp sprayer. The conventional spray boom is removed altogether for UAN application. The large sprayers can carry 1000-1200 gal of solution & control it easily w/Raven (or comparable) controllers. The local ones are 12r models, I believe. Crop damage is minimal, typically only while turning on the end.

Do any of these exist in your area?