Urine contains the compound called urea, basically it's ammonia (NH3). Ammonia is not good for growing much of anything, that's why we use it in household cleaning. I'm sure there's many ways to make fertilizers at home, I would just buy some liquid Miracle Grow if there was absolutely nothing else available.
Molases for starters, you might wanna post in organic growing. http://forum.grasscity.com/advanced-growing-techniques/565458-blackstrap-mollases-nutrients.html http://forum.grasscity.com/general-indoor-growing/599384-molases.html http://forum.grasscity.com/organic-growing/553745-make-your-own-soil-mix.html http://forum.grasscity.com/absolute-beginners/591493-what-best-soil-mix-beginner.html http://forum.grasscity.com/organic-growing/580381-compost-teas.html http://forum.grasscity.com/absolute-beginners/572058-my-soil-mix.html Rep please, thanx, S.S.
^^ Is correct. It will actually kill plants in large quantities. Some additional info: There are two types of bacteria which break down the ammonia. The first stage consists of converting the ammonia to nitrites. These are then broken down into to nitrates which plants can consume. One chemical fertilizer is ammonium nitrate which plants can consume directly and can be used for making crude bombs.
Urea has to be broken down by microbes before the nitrogen it contains becomes useful to a plant. While many comercial fertilizers contain urea nitrates, diluting your own piss simply won't work. Seymor's right too, molasses is great during flowering. Unsulphered Blackstrap Molasses is what you want 1tsp/gal. I also heard wood ash is a decent source of P, but never tried it.
To answer your question, in experiments I've done, it DOES in fact contain a decent amount of Nitrogen, and did not harm my plants AT ALL. Just make sure it's diluted enough...about 2 tbsp/gallon.