Dekalb

No apology needed. I know you didn't start this often quoted rumor. I heard it many years ago. It's been discussed often in the past here on AgTalk. There doesn't seem to be any proof of using NH3 to build runways in WW2. Perhaps you've thought about just "how" it was transported, stored, and used on islands to build runways. Seems impractical. 

Besides WW2 runway stories, is there any modern day studies showing that NH3 injected in the ground actually "hardens" the dirt...permanently? If there is, this vet (US Army, 1968-70, US54830412, 91B20, Augsburg, Germany) would be interested in reading about it.

Again, back to our personal observation after using NH3 on our corn ground after 60+ years is that it doesn't seem to be making our ground hard. That's "here" anyway.