The organic food movement eschews the use of artificial fertilizers, yet we can never forget a simple fact; nitrogen fertilizers were made possible by the Haber - Bosch process, a method literally of turning air into bread, which by some estimates kept a fifth of the world's population alive [4]. (blogs.scientificamerican.com)
Unfortunately, due to the fact that we've been using artificial fertilizers for a very long time the concentration of minerals in the soil today is 70 to 100 % lower than it was a hundred years ago. (fullhealthsecrets.com)
Urine is rich in nitrogen, potassium, and phosphorus, the three main ingredients in artificial fertilizer. (treehugger.com)