View photo . Field permit sign (Rich Earth Institute) 
 
 Waste not, want not. 
 
 The Rich Earth Institute (REI) in Battleboro, Vt., is investigating whether human urine can replace chemical fertilizers. 
 
 
 
 We first learned of the technique over at Modern Farmer. The project, which has enlisted well over 100 volunteers to donate their urine, aims to determine if "essential plant nutrients" found in urine, such as nitrogen, phosphorus and potassium, will work as a kind of all-natural fertilizer. 
 
 It's not as unusual as you might think. Modern Farmer explains that, "Across the Atlantic, studies have long established urine as a powerful fertilizer." 
 
 The article goes on to cite a study done by the Stockholm Water Company. 
 
 
 
 Via Modern Farmer: 
 
 A study conducted by the Stockholm Water Company in the late 1990s diverted urine from four housing projects to a grain farmer outside the city. The scientists concluded not only that urine could replace quick-acting mineral fertilizers, but also calculated that one Northern European adult pees enough plant nutrients to grow 50 to 100 percent of the food requirement for another person. Other successful trials have taken place in China and Mexico, though none as detailed as the Swedish one. 
 
 National Geographic spoke with researcher Debendra Shrestha of Tribhuvan University in Kathmandu, Nepal, who said that Nepalese farmers have been using human urine on crops for centuries. 
 
 But does it work? According to National Geographic, it did for Shrestha. After conducting an experiment that featured sweet peppers grown in soil with different combinations of urine, compost, and urea ― "the main nitrogen-containing chemical in human urine" ― the researchers found that plants grown in soil that "had a combination of human urine and compost grew the tallest, yielded the most peppers, and had the most total fruit weight per plant." 
 
 That study's results were published in Scientia Horticulturae. 
 
 Another study investigated the effect that urine and ash had on growing beets. The researchers found that "urine with or without ash can increase the yield of red beet and furthermore the microbial quality and chemical quality were similar to the situation in mineral-fertilized products." 
 
 Yet another study that focused on tomatoes found similar results. 
 
 Still, there are questions. As Modern Farmer notes, traces of pharmaceuticals that can show up in urine are also being studied by REI, with the help of two universities. 
 
 
 
 Follow Mike Krumboltz on Twitter (@mikekrumboltz). ||||| In 2012, Kim Nace, Rich Earth’s administrative director and partner Abe Noe-Hays collected 600 gallons of urine from friends and neighbors. The next year, the organization brought in about 3,000 gallons from 170 human volunteers. Rebecca Rueter, a board member for Rich Earth, invited members of the local women’s chorus to donate their pee. 
 
 Rich Earth hopes to double that amount this year to a round 6,000 gallons — enough to fill a third of an average American swimming pool. “We’ve given volunteers a few things to make it easier — some funnel devices and things like that,” says Nace. 
 
 Urine contains nitrogen, phosphorus and potassium — essential plant nutrients that are usually mined from the earth or the air for agricultural use. 
 
 The project aims to test human urine as a replacement for chemical fertilizers. Urine contains nitrogen, phosphorus and potassium — essential plant nutrients that are usually mined from the earth or the air for agricultural use. In collecting human urine, Rich Earth is diverting the same chemicals from waterways to farms, making a potentially harmful substance a boon to crop production. 
 
 The urine collection scheme has had some unintended consequences for Nace’s home in Brattleboro, which hosts the so-called “urine depot.” There is a buzz of conversation as volunteers drop off 5-gallon jugs to be loaded into larger holding tanks. “When people realize that they produce something every day that can be helpful to the environment and the earth, it’s a very wonderful feeling,” says Nace. 
 
 Poop Versus Pee as a Fertilizer “Urine Separation — Closing the Nutrient Cycle,” the exhaustive Swedish study of using urine as a fertilizer, compares the pros and cons of using solid human waste and liquid human waste to help grow crops. According to the study, urine contains many of the chemical elements plants need, but solid waste has the lion’s share of organic material such as carbon, fiber and beneficial microorganisms. 
 
 At the moment, solid human waste is much more likely to become fertilizer in the U.S. Despite strict regulations from the EPA, almost 50 percent of “human biosolids” return to farmland in the states. As far as Rich Earth knows, they are the only project in the country legally returning human urine to the soil. 
 
 Which is surprising. Fecal matter requires a much greater amount of attention to be processed into safe fertilizers or grey water. On the other hand, urine only makes up 1 percent of the liquid sewage flow in Sweden, and it’s rarely separated from the rest of the stuff that gets flushed and turned into fertilizer. To capitalize on the plant nutrients in urine, the liquid would need to be separated at its source rather than processed at a treatment facility. 
 
 Jay Bailey, who owns and operates Fair Wind Farms with his wife Janet Bailey, volunteered a few hay fields for the initial stages of the project in 2012. He spread a urine solution from the Brattleboro volunteers over the crops from a horse-drawn applicator and, come harvest time, observed that urine-treated fields were twice as productive as unfertilized controls. The success earned Rich Earth a $10,000 SARE grant from the USDA to expand the trials at Fair Wind in 2013. This year, urine will go to three farms for collaborative trials. 
 
 But would Bailey — who makes his living operating a small farm — opt for pee-power if he wasn’t part of an experiment? “With the cost of fertilizer these days, I would certainly give it very serious consideration,” he says. 
 
 Across the Atlantic, studies have long established urine as a powerful fertilizer. A study conducted by the Stockholm Water Company in the late 1990s diverted urine from four housing projects to a grain farmer outside the city. The scientists concluded not only that urine could replace quick-acting mineral fertilizers, but also calculated that one Northern European adult pees enough plant nutrients to grow 50 to 100 percent of the food requirement for another person. Other successful trials have taken place in China and Mexico, though none as detailed as the Swedish one. 
 
 Rich Earth acknowledges that the biggest hurdle to their work is public perception of lingering buckets of pee, or the so-called “ick factor.” Urine is actually sterile when it exits the body, save for rare cases of a bladder infection or salmonella poising. REI has nevertheless developed two strategies for eliminating the risk of pathogens, either by solar pasteurization or long-term storage in a warm greenhouse. Both have proven effective. 
 
 A real concern for Rich Earth? Left over pharmaceuticals that end up in urine. The EPA has selected Rich Earth for funding to conduct a study of traces of drugs in urine with the help of the University of Michigan and SUNY Buffalo. 
 
 But even if there is minimal risk to personal or public health, Nace realizes that only a chosen few will ever be willing to collect their own urine with jugs and funnels. A much more realistic option is urine-diverting toilets, which again the Swedes, masters of pee, have reliably engineered. 
 
 1 Volunteers find the optimal dilution rates for 2013 field trials. 2 A greenhouse built to treat urine tanks for pathogens. The urine is sanitized after 30 days at or above 20°C (68°F). 3 Board member Dan Marks and Research Director Abe Noe-Hays built a solar pasteurizer in 2012 to sanitize 50 gallon batches of urine. 4 Over 170 volunteers have donated urine to the project. Photos and captions courtesy of the Rich Earth Institute. 1 Volunteers find the optimal dilution rates for 2013 field trials. 2 A greenhouse built to treat urine tanks for pathogens. The urine is sanitized after 30 days at or above 20°C (68°F). 3 Board member Dan Marks and Research Director Abe Noe-Hays built a solar pasteurizer in 2012 to sanitize 50 gallon batches of urine. 4 Over 170 volunteers have donated urine to the project. Photos and captions courtesy of the Rich Earth Institute. 
 
 Nace keeps one in her home, where it’s become something of a tourist attraction for people coming to learn about the project. (She welcomes everyone to use her bathroom, but appreciates a donation in return.) The toilet has a division three-quarters of the way toward the front of the bowl. Urine goes in the front side where it’s piped to a holding tank; all other waste and toilet paper falls to the back for composting. 
 
 The only complaint on the toilet, says board member Konrad Scheltema, is that the men have to sit to use it. Then again, the requirement keeps Nace’s bathroom clean. 
 
 Vermont might be one of the more progressive states in the country, but even as regulators and politicians support the project, there remains a fair number of skeptics coming to Rich Earth with questions. Does it smell? Sure, says Bailey, but only for about an hour after application. Any ammonia-based fertilizer smells. Is it legal? Rich Earth has met repeatedly with Vermont’s Agency of Natural Resources, which oversees waste water management, to make sure they are meeting all public health standards. 
 
 Most inquires come from people worried they are literally pissing away a valuable fertilizer, all with the same question: How can I help? 
 
 Nace refers all potential urine donors to the Rich Earth website. ||||| People have been using manure as fertilizer for millennia. But scientists now believe they can turn human urine into liquid gold—as composting material. 
 
 The premise is simple: Pee is rich in nitrogen, which plants desperately need. Commercial fertilizers boost plant growth and yield by providing abundant nitrogen to the plant’s roots. 
 
 Of course, commercial fertilizers can harm the environment if they get into lakes and streams. As well, not all farmers in the developing world can afford to buy fertilizer for their crops. Enter pee. (Related: “Human Pee With Ash Is a Natural Fertilizer.“) 
 
 Debendra Shrestha, a researcher at Tribhuvan University in Kathmandu, Nepal, noted that Nepalese farmers have been applying human urine to their crops for centuries. 
 
 Unlike commercial fertilizers, urine is free and abundantly available. Plus, it doesn’t seem to have any harmful environmental effects. The main question that remained was whether it actually worked: Would plants grow better when their soil was treated with human urine? 
 
 Pee Power 
 
 To answer this question, Shrestha and colleagues grew sweet peppers (Capsicum annum) in soil that had various combinations of human urine, compost, and urea—the main nitrogen-containing chemical in human urine. The urine was collected from communal toilets in Kathmandu, whereas the compost was sourced from cow manure. (Also see “Urine Battery Turns Pee Into Power.”) 
 
 The plants grown in soil that had a combination of human urine and compost grew the tallest, yielded the most peppers, and had the most total fruit weight per plant, according to the study, published recently in the journal Scientia Horticulturae. 
 
 The scientists say the pee was so effective because of several factors working together. For instance, the mix of compost and urine decreased the amount of nitrogen lost in the soil while making more carbon available to the plants. 
 
 “We need to start moving toward the application of urine in combination with compost,” Shrestha said in an interview with <a ” href=”http://www.scidev.net/en/south-asia/news/crop-thrives-on-urine-compost-mix.html” target=”_blank”>SciDev.Net. 
 
 To Pee or Not to Pee? 
 
 Still, not everyone is convinced. Other studies in Africa that used a combination of human urine, human manure, and poultry manure found that these substances did not yield more crops than commercial fertilizers did. (See “Human Waste to Revive Haitian Farmland?”) 
 
 The use of human urine, noted Surendra Pradhan, a researcher at the International Water Management Institute who is based in Ghana, has major problems, according to SciDev.Net. 
 
 For one, although urine is freely available, not all cultures might take to the idea of using it on their crops. What’s more, it needs to be used along with compost for it to be effective, since urine alone doesn’t have enough nutrients to sustain plant growth over several years. (Read more about sustainable agriculture.) 
 
 Last, although commercially available fertilizers aren’t free, many governments do subsidize their availability, which may decrease the overall appeal of urine-based fertilizers.
– Nitrogen, phosphorus, and potassium are among plants' key needs—and your urine contains all of them. That's why Vermont's Rich Earth Institute is studying the use of human urine as fertilizer, Modern Farmer reports. There's already plenty of evidence that it works. Yahoo cites one study, earlier reported by National Geographic, in which a researcher found that a blend of urine and compost resulted in taller sweet pepper plants with more peppers. A Swedish study, meanwhile, sent urine from housing projects to a farm. Researchers found that one adult's pee provides enough plant nutrients for 50% to 100% of another person's diet, Modern Farmer notes. A farmer working with the Rich Earth Institute also found urine to be highly effective in a 2012 field test, results that helped the group get a $10,000 USDA grant. Last year, the institute collected some 3,000 gallons of pee from 170 people. "When people realize that they produce something every day that can be helpful to the environment and the earth, it’s a very wonderful feeling," says its administrative director. But hurdles remain: For instance, human urine can contain remnants of medications.