Urine is a source of nutrients for plants, especially nitrogen. However, if processed incorrectly, it can be a pollutant, leading to:
- eutrophication of water supplies.
- bad odors when not properly managed.
Use as fertiliser
Urine ideally should not be mixed with feces if composting (humanure) is planned. Mollison's system can be used to make fertiliser from urine. See also: Bokashi compost tea
Extraction of precious minerals
Struvite can be created from the urine and collected, by first adding magnesium to the urine. The remaining liquid can be sprayed over farming fields. The magnesium then binds with the phosphate in the urine.
Also, perhaps that the urine can also generate some power first, see references at Alternative_ICE_fuel_generator#Hydrogen