Urine, constituents

Urine is sterile when it leaves the body (if you don't suffer from septicaemia or some similar disease).

It is an excellent fertilizer (diluted with water 10-15 times in order not to 'burn' the plants)

As a rule of thumb, the uine from one person in one day is enough to full-fertilize one square meter of land.

It is easily affected by bacterias, which thrive on the urea. By that, ammonia is freed. It smells bad and causes notrigen loss.
To avoid that, you can
- acidify e.g by adding sugar and lactic aicd bacteria
- cool e.g. by burying the tank in the soil too keep it at a low temperature. This is a good practice in areas with low average temperature.
- impede bacterial growth by adding a detergent
- mix urine with charcoal, let it soak so the nutrients in the urine are added to the char. Then, mix the char with the soil. Plant growth will be greatly enhanced.
Mixing urine with faeces is a fast way to produce foul smell. It is because the faeces contains bacterials (e.g. micrococcus ureae) which very fast break down urea - hence the ammonia smell. Other agents are also freed, e.g. skatole, which is one of the most foul smelling agents we know of.
On contact with soil, the urea is also readily degraded, which leads to a fast loss of ammonia, and by that nitrogen.
When using urine as a plant fertilizer, it is important to put it into the ground and cover it with earth or dilute it and water it down.

Commonly, however, urine is regarded as a pollutant and is mixed with faeces in the sewerage water.