I've often thought the exact same thing -- NH3 would do a heck of a job on ground-dwelling critters. And since we are growing so much more grass retail hay, we need more N in our fertility programs.

Can you guys in NH3-using country tell me some numbers/issues with NH3 knives, implements, nurse trailers, costs of equipment and the N (per unit) etc?

We have literally NO NH3 infrastructure here, so we'd be starting from scratch.