Not to be contrary but having lived most of my life in the Mushroom Capital of the World I'm more than familiar with the smell of burning horse manure (cured manure is the growth medium of choice for many mushroom growers). When those piles of curing manure are turned or, heaven forbid, catch fire, you don't want to be downwind of them. I'll take my neighbor's stinky cigars anytime.

Back in the 50's they use to sterilize the soil they combined with the manure with CS gas, or it's commercial equivalent. You really didn't want to be downwind of that operation. Of course, in those pre-OSHA days, no one was too concerned with respiratory safety.

To this day still not a big fan of mushrooms.