You know, this is really funny. I was literally just looking up natural sources of nutes, and was reading up on manures. I have access to cow and horse manure, as there are pastures all over my area, so I was planning on making a run across the road for some tomorrow. Then, I came across an article discussing the whole thing with urine, and was astounded to read that human urine is actually a common and effective plant fertilizer. It contains high levels of nitrogen, phosphorus and potassium, which are three of the biggies we give our plants during vegetation. Honestly dudes, it's completely legit. Yeah, it's nasty, but it's effective, and also FREE. If you do want to try it, you're supposed to dilute it in water, and avoid pouring it onto the leaves so as not to cause nitrogen burns, the same as chemical nutes.
I'd recommend many of you dudes actually read up before you go slamming people. Here:
http://www.ecosanres.org/pdf_files/ESR-factsheet-06.pdf