For farm use, it’s typically a tank on wheels, pulled behind a tractor. The ammonia is injected into the soil.
Here’s one that blew out.
http://www.doli.state.mn.us/ccld/BoilerIncidentsPressure.asp
We never used it on our Farm, for fertilizer. There were other, better, safer options. But I remember seeing train tank cars, 50-100 long, slowly moving thru the county just to the north, on their way east yo tank farms, where it was offloaded and stored.