Nitre in a sentence as a noun

I’ve read the term “nitre pit” and am guessing it’s pee plus dirt, with compost in a separate place so the ammonia doesn’t interfere with composting. To separate poop and pee in general, we’ll have to change our habits: “Aiming is important, and men must sit.

Nitre definitions

noun

(KNO3) used especially as a fertilizer and explosive

See also: saltpeter saltpetre niter