Human Urine as a Fertilizer

Boy urinating on tomato plant

I became interested in gardening at a young age. A neighborhood buddy, Donnie, introduced me to the joys of vegetable gardening. His mother and mine were coffee clutch friends, and Donnie would frequently bring fresh vegetables – tomatoes, eggplant, corn etc.. to my mom, who gleefully accepted. Donnie’s produce became a staple of many neighborhood meals, that is until his gardening secret was revealed. What was The Secret ? Donnie pissed on his peppers, and tinkled on his tomatoes.

Boy urinating on tomato plant
At the time, I thought it was hilarious, especially the look on Moms face when she found out how he got his veggies to grow so huge and Tasty.

For years thereafter, it was a tale told from time to time which would always elicit a hardy chuckle from guests .

When I grew my own gardens I always made sure not to pee on the plants … when anyone was looking.

In actuality fresh urine is an excellent sources of plant nutrients. All the basics are there nitrogen, phosphorous, potassium and trace elements . Being liquid, Urine is easily absorbed through the root systems. Not only that, it’s free and in constant supply.

Fresh Urine is clean and bacteria free, it can be drank in survival situations, and astronauts drink it in a recycled – purified form. Urea in urine degrades into Ammonia after sitting for sometime, which is what generates the nasty stench . Once it degrades to the point of smelling like wet stale baby diapers it is no longer a good idea to pour it on your plants, but the compost heap would certainly benefit from it.

Urine is primarily water, only about 5% is a mixture of urea, minerals, salts and assorted non toxic body wastes. Nitrogen is present in several forms as well as sodium, potassium, calcium, magnesium, sulphate and more.

In Uganda, there is a small farming community, The Nezikokolima Farmers Group, who use Human urine to fertilize their gardens, they say their vegetable yields are impressive. [Uganda: Human Urine Safe As Fertilizer – all Africa online]

At the University of Kuopio in Finland a mixture of wood ash and human urine was found to perform as well as expensive commercial fertilizers, while being ecologically safe. The Study group fertilized several groups of greenhouse tomatoes: one with human urine and birch ash, another with commercial mineral fertilizer, and another with straight urine.

The plants fertilized with urine and wood ash produced almost four times more tomatoes. The plants that received straight urine produced slightly more than those receiving the urine and wood ash mixture.

“In one year, the average human being produces enough urine to fertilize 6,300 tomato plants.” – [Food Crop Fertilizer Features (Gulp!) Human Urine, Sept 9, 2009]

Fresh Urine is best, once it develops the ammonia smell, it’s nutritional value has declined and it is best dumped on the compost heap, I would also not recommend peeing directly on tender young plants and seedlings. A diluted urine would be best in this case , I’ve heard recommendations up to 50 parts water to One part pee – which is absolutely ludicrous ! 5 parts water to one part pee is more than a sufficient dilution ratio.

So in conclusion – the next time you’re tilling in the garden and feel the urge to go, don’t hesitate to whip it out, or squat as the case may be, and sprinkle a tad. Just make sure no one is looking.