Ron,

 "Here"    the Liquid rig of choice would be built around yetter colter w/ knife .(no splatter) As has been already stated, running as close as possible to keep from pluging. John Blue pump, running through Red Ball's and then orfices, located about a foot above the knife  @ about 20 PSI (enough to equalize flows across the width of the tool)

It would be 3 pt mounted with tractor carrying fert onboard ( I carry 750 gal in 900 gal tanks) To much weight to carry full. It would be a wing type rig (40' wide) w/hydraulic wings that lock down. (wings shouldn't ride up)( 12 row) Some have high clearance pull-behind tanks.(1000)

Pumping speed: That is an issue. Even with a 6.5 hp and large cast iron pump probably takes 15 min to pump 750 gal. Transports have 11 hp X 3" pump. About 30-45 min to off load 4600 gal.

Rust: yes rust, especially when carrying on tractor. Keep all leaks fixed, best as possible, wash on days off and the big one at the end of season. My rig is about 20yrs old.have to have a torch handy if I need to lossen most bolts on the coulter area.

Still, way more Urea goes out on cotton and corn around here.......maybe 80% total useage is urea.

At the first of the season we thought there might be a shortage of urea, so many bought nurse tanks for 32 just in case urea ran out.

Of course.......the only shortage........ was the money to pay for the stuff........, but were used to that arn't we?

Have a good day,

John