STEVE INSKEEP, HOST:
And I'm Steve Inskeep with the story of an element considered vital to sustaining all life on this planet. Phosphorus is in our DNA, and it's also critical to our food supply. Most fertilizers use phosphorus. There's no known substitute. Most of the phosphorus in the world is controlled by a single country, Morocco, and there is a finite supply. So some scientists are concerned we could run out. Karen Duffin from our Planet Money team reports on a way to conserve it.
KAREN DUFFIN, BYLINE: It was a Wednesday night at All Souls Church in Brattleboro, Vt., and the women's chorus was practicing like they do almost every week.
BRATTLEBORO WOMEN'S CHORUS: (Singing) And when I'm with you...
DUFFIN: Every practice, there is a break for announcements - you know, library fundraising and school bake sales. That night, Rebecca Rueter, a member of the chorus, stood up and said...
REBECCA RUETER: I would like to ask you to think about collecting your urine and bringing your urine, you know, in a little jar - or a big jar - to Kim's house.
DUFFIN: She asked them to donate urine because urine is packed with valuable nutrients, in particular phosphorus. It's in the food we eat and then ends up in our waste. Rebecca was on the board of a new research institute in Brattleboro.
RUETER: The Rich Earth Institute - and we really need as much urine as possible in order to test our hypothesis.
DUFFIN: The idea was this - if we recycled our nutrient-rich urine instead of flushing it, could we have a sustainable supply of phosphorus, and thus fertilizer, forever? So they formed a committee...
KIM NACE: We created the Urine Brigade.
DUFFIN: This is Kim Nace. She founded the institute along with an environmental scientist named Abe Noe-Hays.
NACE: There were, like, six of us. We sat out on my back porch. And we said, how are we going to get this urine from people? What are we going to do?
DUFFIN: The brigade recruited at that women's chorus, at churches and events, sponsored a float in the local parade.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED MAN: Give me a P.
UNIDENTIFIED PEOPLE: P.
UNIDENTIFIED MAN: Give me a P.
UNIDENTIFIED PEOPLE: Give me a P.
DUFFIN: The letter P is, coincidentally, the symbol for phosphorus on the periodic table. By the end of that first summer...
NACE: We had 60 people and 600 gallons of urine.
DUFFIN: They sanitized the urine - actually pasteurized it, like orange juice. And then came the real test.
NACE: OK. So the next place we're going to go now is to the farm.
DUFFIN: Kim and I drove to the outskirts of town, where Dean Hamilton runs a hay farm.
You run a hay farm that is entirely fertilized by human urine.
DEAN HAMILTON: Yup, yup.
DUFFIN: I asked Dean how well it was working.
HAMILTON: It easily can double, you know, the yield in my hay.
DUFFIN: The institute has also done research with the USDA, the EPA, National Science Foundation and lots of others. And their scientific tests show pretty much the same results.
Larger companies are also doing this kind of thing at scale, working directly with sewage plants in cities like Chicago and London. So far, it looks like they're right.
NACE: We are all our own little fertilizer production factories.
DUFFIN: Probably not going to put that on my Tinder profile anytime soon. And of course, collecting urine alone won't save us. But for now, I'm gonna take this as a tiny drop of hope.
For NPR News, I'm Karen Duffin.
(SOUNDBITE OF MY DAD VS. YOURS' "TANZ MIT UNS") Transcript provided by NPR, Copyright NPR.