It seems that engineers have found a new use for human urine: fertilizer for fish food. It seems that diluted human urine could serve as an ecologically friendly fertilizer for zooplankton, which serves as a food source for many types of fish. Researchers appear to have been looking for a fertilizer that avoided some of the problems of commercial fertilizers. Human urine was the most successful fertilizer of those tested, including cow dung, poultry droppings, vermin compost, and cow urine.
It would be interesting if human urine was used as a fertilizer…it would certainly be a good way to recycle something that would otherwise be waste.