....I can't speak for your area, but I call B.S. as a "here thing". We have applied NH3 for many many years. One of my earliest memories is of the old man having me grab him a beer as he was transferring NH3 from a nurse tank and watching him flash chill it in the bleed off vapor.

Very cool, to a young 5 year old.

Even for those many years of NH3 apps, I am loaded with worms. The ditchers even comment on it, as we installed 36,000+ feet this spring & in some places I could find 4-5+ night crawlers/foot of trench. Red worms are the same way.(hindsight, I wish I would have taken some pics).

The Aglime council had a great chart and information of the acidifying affect of the different fertilizers, but for some reason their web site is not coming up. Here is a similar chart. 

http://www.agry.purdue.edu/ext/forages/publications/ay267.htm

I actually lost more worms(my opinion) in a 2.5 inch rain event(on saturated soil) about a month ago. You could see & smell the dead worms drowned in the standing water.