Using Urine As Fertilizer, Does It Work?

in #garden2 months ago

Using urine as fertilizer has been a staple in farming for centuries but in modern times this practice has taken a backseat compared to "artificial" supplements and fertilizers. Yet, is there any benefit for using urine as a fertilizer or is that just folklore nonsense that was replaced by empirical science?

I've made a comment on someone else's post who mentioned using urine as a fertilizer for their cannabis plants, so it got me thinking of the benefits and the negatives of using urine as a fertilizer. I conducted a few days of dedicated research into pee, why? I don't know, I guess urine and the process of producing urine or Urea, interests me for right now. With that being said, here are the main concerns and benefits of using urine as a fertilizer for not just Cannabis plants but most angiosperms (or flowering plants), ferns and related beings:

  • The Urine you produced before peeing (urination) doesn't contain the same amount of nutrients or pH levels you'll produce during a different time. Not all urine is the same, even from the same person. There is no telling if you have over fertilized your plants until the plant reveals it to you by the discoloration of the leaves/stems etc. The testing of the soil for pH imbalance is essential, if you're growing indoors and primarily using pee as a fertilizer.
  • The nutrients that are provided from urine contain primarily Nitrogen, Phosphate, Potassium and Chloride with many other trace elements as well in smaller amounts. Potassium and Nitrogen are essential elements for plants.
  • Urea itself is sterile with no bacteria, however, urine has a small chance of passing diseases. An individual may have internal bleeding, or there may be an infection in the bladder or the urinary tract which may end up in the soil. The plants can also pass diseases to their leaves, however, this is extremely rare. Not necessarily something to be concerned about.
  • The bladder is the main location where bacteria can build up after the production of Urea. Human Female-produced urine contains more bacteria compared to male-produced urine, on average.
  • Your soil will smell like ammonia over time and it may smell bad if not properly watered down.

There are numerous amounts of benefits to using Urine with almost no significant drawbacks. The main concern with using urine is over fertilization and the likely chance of pH imbalance. The other concerns are insignificant, so for me, using urine is the best cheap option to fertilize your crops. Also, its a great way to produce less liquid waste which will end up in a water treatment facility. Any reason to not flush a gallon of water just for a liter or two of pee is a net benefit for society.

If you want to use urine, by all means use it! It's a great alternative.


It is best to keep a few degrees of separation between the human waste stream and food supply. Urine is less like to spread disease than poop, but the trouble of separating the two is not worth the effort.

IMHO, farmers do best by studying the microbiology of their soil and then adding things to the soil to improve their particular crop.

Ammonia it's used often .. chicken feces is normally the go-to for farming though