It is good for plants and vegetable garden: human urine, an unexpected, effective and less polluting fertilizer

“Go pee on the rhubarb!” : This novelty’s advice inspires researchers and NGOs to find an alternative to chemical fertilizers, reduce environmental pollution and feed a growing population thanks to an unexpected ingredient, human urine.

Synthetic nitrogen fertilizers enhance agricultural production. But when used in abundance, it pollutes the environment. Their prices are rising, even with the war in Ukraine, which has burdened farmers.

What to replace it? for us peeanswers researchers including Fabian Escolier, who has never forgotten his grandmother’s advice and is considering overhauling more sustainable diets.

For growth, plants need nutrients, nitrogenThe phosphorous And potassium“, explains engineer and coordinator of the OCAPI Research Program in France. When we eat, we ingest these nutrients before they are “excreted, often via urine”, he continues.For a long time, urban waste has been used in agricultural fieldsbefore being replaced by chemical fertilizers.

But when these nutrients are released in very large quantities into rivers, they promote an explosion of green algae, for example, and represent “a major source of nutrient pollution,” asserts Julia Cavici, of the Rich Earth Institute, based in the US.

Transcend Preconceptions

Separating and collecting urine from the source requires rethinking the latrines and collection network and overcoming some preconceptions.

Separation of urine from toilets was tested in Swedish eco-villages in the early 1990s, and then in Switzerland or Germany. Trials are taking place in the United States, South Africa, Ethiopia, India and Mexico. In France, projects appear in Dol-de-Bretagne, Paris, Montpellier.

“It takes time to introduce environmental innovations, especially one as radical as urine separation,” says Tove Larsen, a researcher at the Swiss Federal School of Water Science and Technology (Eawag).

She explains that early generations of toilets with a urine separator, considered impractical and ugly, or a fear of bad odors might act as the brakes. The researcher hopes that a new model developed by the Swiss company Laufen together with Eawag should solve these difficulties.

Fabien Gandousi owns Restaurant 211 in Paris, which is equipped with dry toilets where urine is collected. “We’ve got pretty positive feedback, people are a little surprised, but (..) they don’t see much difference compared to the traditional system.”

“There are hurdles to overcome,” comments Marine Legrand, an anthropologist and member of the Okapi Network. But “we begin to understand how precious water is” and “defecating in it becomes unacceptable.”

Are people still ready to eat urine-enriched foods? The study shows marked differences between countries. The acceptance rate is very high in China, France or Uganda, but low in Portugal or Jordan.

“This topic touches intimately,” analyzes Ghislain Mercier, of Paris and Metropole Aménagement which is developing an eco-zone in Paris with 600 housing units and shops…Urine will be collected there and fertilize Parisian green spaces.


According to him, there is great potential in offices and homes that are not connected to the sewage network or slums that do not have sanitation facilities.

However, it is necessary to get the population to comply, to rethink the pipes, to counteract the inappropriate legislation …

Once harvested, the urine must be transported to the fields, which is expensive. Various technologies make it possible to reduce its volume and concentration of urea or even dry it. Rich Earth Institute develops technology solutions to make spreading this fertilizer easy and inexpensive for farmers.

Since urine is not usually a major vector of disease, it does not require extensive processing for use in agriculture. The World Health Organization (WHO) recommends letting it rest. It is also possible to wear it.

Urine is still struggling to establish itself As an alternative to synthetic fertilizers. But with rising gas prices and many countries wanting to strengthen their food sovereignty, regarding the war in Ukraine, “economic restrictions will catch up to us faster than we thought and make the issue more heard,” comments Ghislan Mercier.

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