Anya Subich

Planet needs your pee!

urine can save the future of agriculture

We do not just take a leak. We ruthlessly flush king Solomon’s mines into a toilet bowl. Besides water and urea, human pee contains about 10 precious elements - a few of these being calcium, magnesium, sulphate and phosphate. In this age, when humanity is steadily running out of natural resources, we might search for alternative mineral fields within our own bodies. Two years ago, Amsterdam’s major water corporation, Waternet, proposed an eccentric Green Urine campaign aimed at converting citizens’ pee into a fertilizer for the city’s green roofs.


waterless urinals - SHUTTERSTOCK

Scientists sound an alarm: phosphorus, potassium and nitrogen, widely used for soil fertilization, are about to become scarce in the nearest 100 years, which means we can expect a global agricultural crisis to follow. Meanwhile, guess what - these nutrients can be easily detected in human urine. An idea to make urine serve a public good first attracted attention when a group of scientists from the University of Florida conducted a study on alternatives for scarce resources. In laboratory conditions they managed to extract 97 % of minerals using ion-exchange technique. Roughly speaking, during this process magnesium is being added to urine, where it sticks to ammonium and phosphate, forming Magnesium Ammonium Phosphate Hexahydrate, also known as Struvite (MgNH4PO4•6H2O). Struvite in turn, is a great natural fertilizer that can be used to boost a crops life cycle and cure plant diseases.

The same principle is involved when wasted water is being processed in urine-diverting urines. During the International Water Week, demonstration urinals were set up at La Place de Bourse in Amsterdam, and the men - for now only men - of the city were encouraged to donate their invaluable product for the sake of the future. Waternet then claimed that pee from 1 million Amsterdamers is enough to produce 1,000 tons of fertilizer each year. Nowadays, Waternet’s idea is being recognized as a green start-up hub in Amsterdam-North, where the Metabolic cleantech firm has installed urine and gray water filters into office spaces.


When Nature Calls-urinal - by Eddie Gandelman Eddie Gandelman, Tuvie

Similar projects have already taken place in different parts of the world. In 2002, the Swedish town Tanum underwent a massive installation of urine-diverting toilets. And in 2012 Scientific American reported:

Nepalese farmers using urine to boost their crops as a part of an NGO campaign, held in the region.

But actually…it’s not a big secret that urine has been used in agriculture since times immemorial. Medieval writer and agriculturist Gabriel Alonso de Herrera mentions in his works that urine was used to boost the old vineyards and cure plant diseases in ancient Rome and Greece. At the end of the day, we inevitably return to the earth's roots.