Norfolk Master Gardeners
830 Southampton Ave., Ste 2069
Norfolk, Virginia 23510-1045
Free Fertilizer – Frugal Gardening Tips
This has been one of my favorite and most controversial gardening tips that I’ve been sharing with people for over a decade. Any time I talk about this tip I get reactions from curiosity to disgust, to nervous jokes. Before I get into the story of how I first learned about it I ask you to do one thing for me: keep an open mind.
In the summer of 2008, I met a farmer at a local farmer’s market in Kansas City, MO. His produce was always amazing. He claimed to use no chemical fertilizers and no pesticides in his garden. After a year getting produce from him, I started asking how he did it. He would smile and tell me it was a secret and the next time I saw him we would repeat this cycle. It was 2011 when he finally gave in to my request, but first, he made me promise never to reveal his identity. I agreed and as soon as he told me I went home and researched the topic. At the time there was less information on the topic than there is now but there was some and I was amazed by what I found.
What is this wonderful, free, easily accessible fertilizer? Human urine. This is where I lose a lot of people, but I want to point out something to everyone. Gardeners trying to avoid chemical fertilizers often use blood meal. Blood meal is the reclaimed blood from animals, often times cattle and pigs. You can find soil amendments like crab meal, fishmeal, bone meal, feather meal, etc. – all bioproducts of animal processing. We use composted bird, cattle, rabbit, and bat manure. The main ick factor is that it comes from humans and not something else. This requires a paradigm shift in how we view resources and where they come from. As an aside: the above-mentioned farmer collected the urine from his whole family and aged it, (aging discussed later on), so he had enough for his farm.
What are some safety concerns to the use of urine? Your own urine used on your own plants has little to no concern at all. You can’t really catch anything from yourself. A study by the University of Michigan discovered that aging urine destroyed almost all antibiotic-resistant bacteria (Moore, 2020). The aging process from weeks to months further makes the urine safe from bacteria.
What about its effectiveness? Research done comparing urine to commercial fertilizers when growing beans showed that beans fertilized with commercial fertilizers produced slightly better than with urine but the yield when using urine was still much higher than when no applications were applied (Ranasinghe, et al, 2016). A study done with pumpkins showed that commercial fertilizer produced larger fruits, but urine-fed pumpkins had smaller but higher production of fruits (Pradhan, 2010). In research with amaranth, they found that the production was equal to commercial fertilizer (AdeOluwa, et al, n.d.). In all these studies the tested nutrient quality was found to be equal. They also tested for pathogens. The urine-fed vs. commercial-fed showed no differences in pathogens in the environments. Soil tests were done and higher microbial content was found in some of the soil tests where urine was used. It has also been successfully used for beets, tomatoes, cucumbers, and cabbage (Grunbaum, 2010).
But how do we use this renewable resource? Urine by itself is too strong and must be diluted. There are a lot of ratios that can be found all over the internet and in research. The general consensus is that it should be diluted with water to a 1:10 ratio (Pleasant, 2022). That is, one part urine to ten parts water. This will keep from burning your plants. Of course, more sensitive plants need less, and more hungry plants could use more.
Maybe feeding your plants this way is still just a little too ick for you, but you still want to recycle these nutrients. Urine can be added to your brown organic matter, like leaves, cardboard, etc., to help speed up composting and add vital nutrients (Perrone, 2009). It’s also been found that adding urine to your compost can speed up the process of creating that rich beautiful compost we all so desperately need (Writer, 2012).
The average person produces 2 liters of urine a day (Urine 24-hour volume: MedlinePlus Medical Encyclopedia, n.d). That’s 2 liters of potential fertilizer going down the drain. There is also the utilization of fresh water to dispose of it in our toilets. There is also the energy and resources used at wastewater treatment plants. All this could easily be diverted.
Human urine has also helped the lives of women. In Niger, a large-scale experiment was done with Oga (urine rebranded) and very poor farmland. In Niger if women farmers can even get land to farm on it’s often the poorest quality (Koumoundouros, 2022). This article A Large-Scale Experiment Used Human Pee to Fertilize Crops. Here's What Happened tells the tale of the women who farmed those poor lands and the positive results from using urine. I greatly encourage everyone to read it.
This is not a topic for everyone, and I respect that. But we live in a world where the expense of everything continues to rise. A world where so many people go without nutritious produce to feed themselves and their families. A world where commercial fertilizers do harm to our soil microbial health (Schiffman, 2017). Human urine may be one more stepping stone in the solutions to solve these problems.
References:
Moore, N. (2020, January 22). Urine fertilizer: “Aging” effectively protects against transfer of antibiotic resistance. University of Michigan News.
Ranasinghe, E. S. S., Karunarathne, C. L. S. M., & Beneragama, B. G. G. (2016). Human Urine as a Low Cost and Effective Nitrogen Fertilizer for
Bean Production. Procedia Food Science, 6, 279–282.
https://doi.org/10.1016/j.profoo.2016.02.055
AdeOluwa OO, Cofie O. Urine as an alternative fertilizer in agriculture: Effects in amaranths (Amaranthus caudatus) production. Renewable
Agriculture and Food Systems. 2012;27(4):287-294.
https://doi.org/10.1017/S1742170511000512
Pradhan, S. K. (2010, January 1). Fertilizer value of urine in pumpkin (Cucurbita maxima L.) cultivation. Fertilizer Value of Urine in Pumpkin
(Cucurbita Maxima L.) Cultivation.
https://orgprints.org/id/eprint/16884/
Grunbaum, M. (2010, July 23). Gee Whiz: Human Urine Is Shown to Be an Effective Agricultural Fertilizer. Scientific American.
https://www.scientificamerican.com/article/human-urine-is-an-effective-fertilizer/
Pleasant, B. (2022, December 15). Pee-Cycling for Gardeners. GrowVeg.
https://www.growveg.com/guides/pee-cycling-for-gardeners/
Perrone, J. (2009, November 13). To pee or not to pee. The Guardian.
https://www.theguardian.com/lifeandstyle/gardening-blog/2009/nov/13/composting-urine
Writer, S. (2012, December 1). Urinating on compost pile actually speeds up process. Akron Beacon Journal.
Koumoundouros, T. (2022, June 23). A Large-Scale Experiment Used Human Pee to Fertilize Crops. Here’s What Happened : ScienceAlert.
ScienceAlert.
Schiffman, R. (2017, May 3). Why It’s Time to Stop Punishing Our Soils with Fertilizers. Yale E360.
Urine 24-hour volume: MedlinePlus Medical Encyclopedia. (n.d.). Medline Pluse. Retrieved July 12, 2024, from
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