Where further research is needed, points out soil scientist Janardan Khadka at Nepal’s Central Horticulture Centre, is on whether continuous urine application will affect soil fertility in the long run. The high salt-content in urine could turn soils alkaline, making it harder for plants to access nutrients, said Khadka. The phenomenon is yet to be observed in the field.
Projects to promote the application of urine in agriculture have spread worldwide over the last decade: from pee collection and transport systems designed for 6,500 users in urban Ouagadougou, Burkina Faso; to research on the application of human urine for carp fish farming in West Bengal, India; and more than 135,000 toilets diverting urine in Sweden.
Still, uptake has been slow.
The biggest challenge in urban settings is collecting and transporting all those sloshing liters of urine to the farmer’s fields.
“If an individual produces an average of two liters of urine a day, in a family of six that makes 12 liters a day and 84 liters a week, which is a huge volume, especially if you have to account for three to four months of storage time,” said Prajwal Shrestha, program manager at the Kathmandu-based Environment and Public Health Organisation.
“People are scratching their heads over how to arrange collection systems for those families who don’t want to or don’t have the capacity to use urine and feces on their own,” added Anna Richert Stintzing, a consultant for the Stockholm Environment Institute in Sweden, and lead author of a urine and crop production guide published in 2010.
Researchers are now looking into the possibility of solidifying the valuable phosphorous available in urine, or using urine to fortify compost.
Schönning adds that sewage infrastructure in many cities is already built to transport mixed urine, feces and water to large treatment plants which would require a major investment to change. For these reasons, Stintzing sees urine fertilization as having the most potential in rural settings, where the technology can also contribute to food security and sanitation. She said its promotion should focus on local awareness-raising through demonstrations, and the involvement of “farmers in the planning and implementation of sanitation systems.”
From spinach to turmeric
The way farmers in Sotang have caught on to the new fertilizer illustrates how far such local efforts can really go.
In early 2011, the local Solukhumbu Development Society (SDS) and the Dzi Foundation organized four whole-day training sessions for almost 150 farmers, informing them on the proper application and benefits of urine. They also set up a research and demonstration farm site, prepared training manuals and videos, and supported 11 key farmers to take the lead on agricultural innovations.
Marijn Zandee, technical advisor to the Dzi Foundation, describes how people used to stick marigolds in their noses to block out the offensive smell, but in the course of a year have moved from hesitation to habituation.
Where 37 percent of households chose urine-separating toilets in 2011, almost 65 percent opted for them in 2012, with more expected in 2013. Those who opted for the regular toilets have started voicing regret, some even using makeshift containers to collect their urine, and others have considered purchasing an ecosan pan from their own savings.
Farmers have gradually diversified their palette, experimenting with corn, finger millet, squash, tomato, banana, guava, chilli, cauliflower and cabbage.
“We have created the demand for urine through vegetable production,” Zandee said.
Families may not produce enough urine to apply on their staple crops, but Zandee has set his stakes on relatively valuable crops in small kitchen gardens.