This is a very loaded question, so I'll try to answer it as simply as it is presented... until it washes out or is utilized through a myriad of possibilities.

8 Reasons Why You Should Pee in Your Garden

http://www.lifehack.org/articles/lifestyle/8-reasons-why-you-should-pee-your-garden.html

interesting article

Here's an internal link... Use of human urine?

Fertilizing with human urine

http://www.goveganic.net/article217.html#further_resources

Nitrogen cycle in the soil https://www.youtube.com/watch?v=Ekx84-T5GLk