Disodium ammonium phosphate?
ammonium is used for some stuff. it is usually found in nitrogen
and is related to nitrites and nitrates. it derives from ammonia -
a critical part in the nitrogen cycle.
All in all it is used to decompose poo and stuff and turn it
into nutrients for plants and animals to eat then poo out and over
and over again. one of the processes is nitrification, so you might
want to look that up.