Can you use Human Urine as Fertilizer?

On today’s episode I am going to take a look at one of the questions I have been asked a few times now.  Can you use human urine as fertilizer?

can urine transmit diseases?
Can there be drugs in urine?
Other benefits of urine as a fertilizer

Background on the subject
From the dawn of agriculture and the domestication of animals we have used other animals manures and urines in agriculture as a means to return essential nutrients to the soil allowing for increased crop yields later.

On this month’s instalment of the testing garden assumptions series let’s take a look at the use of human urine in the garden and if it brings any benefits.
Hypothesis
Today’s Hypothesis is that Human Urine can be used as a fertilizer in the garden.
Research
In order to understand this better we need to know what fertilizer potential urine has and if it poses a risk to human health if used in the garden.
Results with general findings
Is Urine a Fertilizer
Urine is the liquid waste stream produced by filtering the blood stream in the kidneys.  Commonly urine is high in nitrogen along with other surplus water soluble elements found in your body.

a 2005 study from Goteborg university in Sweden assessed the recycling of nutrients excreted in urine from urban areas as a a method of ecologically sustainable development. They found that straight urine has an NPK of 18:2:5 while urine flushed with water has 15:1:3.  The study went on to find macro and micro-elements essential for plant growth including Cu, Zn, Cr, Ni, Pb and Cd.

Urine can have a pH between 4.6 to 8 however garden soils usually have sufficient buffering capacity to avoid a change in the pH.

So there is research to support that urine does have value as a fertilizer and is unlikely to be able to change the pH of your soil. The next thing we should take a look at is if urine is safe to use in the garden.
Is Urine Safe to Use in the Garden
In order to understand if urine is safe we should know if it contains anything that may be harmful if someone comes in contact. The first thing that comes to mind is bacteria that may be harmful.

Photo Credit

www.coalphotography.com

http://www.huffingtonpost.com/....2013/09/08/what-is-i

http://www.smithsonianmag.com/....science-nature/from-