A new $3 million grant from the National Science Foundation (NSF) will fund critical next steps in an ongoing program that explores deriving fertilizers from urine. Previous research by Professor Nancy Love, Assistant Professor Krista Wigginton and others has already proven the feasibility of urine-derived fertilizers. This grant enables the continuation of that work and the addition of a key component, the development of a communications program to educate people and help sway them away from an “ick!” reaction.
While we owe our highly productive agriculture in large part to effective fertilizers, which primarily consist of nitrogen, phosphorus and potassium, we don’t currently reclaim or recycle the elements. We essentially produce new fertilizer for each use: Nitrogen fertilizer is produced via an energy-intensive process using natural gas while phosphorus and potassium are derived from mined ore.
If you’ve never thought about what happens to fertilizer after it’s applied to farm fields, you’re not alone. And once you think about it, the obvious answer is the correct one: the plants use the fertilizer as food, the elements become part of the plant, and then, if the crop is wheat or tomatoes or corn or any of the other plants that become part of our meals, we eat them.
After that? Human bodies don’t need most of the nitrogen or phosphorous that we consume and most of it ends up being eliminated in our urine. In the developed world, urine typically ends up in sewage treatment plants in which the “treatment” typically does not affect nitrogen or phosphorus. These chemicals are released into our surface waters where they can cause serious problems.
One of the worst consequences are algal blooms, which can kill fish, diminish recreation and even threaten people—a 2014 algal bloom in Lake Erie rendered the Toledo water supply hazardous, forcing nearly 500,000 people to find alternative water supplies for a few days.
Essentially, we’re discharging nitrogen and phosphorous into our waterways with one hand while the other hand obtains “new” nitrogen and phosphorous from the environment at significant cost.
The use of urine as fertilizer is hardly new. Various cultures around the world have used urine as fertilizer for hundreds, if not thousands, of years. The World Health Organization (WHO) publishes guidelines for urine diversion and reuse.
But the WHO guidelines are intended primarily for places with decentralized waste systems, not for places like the U.S. with sophisticated, centralized sewage processing systems.
With this new grant, CEE is now the center of the United States’ largest program investigating the technology, systems requirements and social attitudes associated with urine-derived fertilizers.
The NSF funding (in a partnership with the U.S. Department of Agriculture) is being used to make advances in two areas. “One is technology,” says Professor Nancy Love. “But we can throw all the technology in the world at this problem and make no progress towards implementation unless the second area is advanced—and that’s the social behavior piece.
“We’re investigating the attitudes people hold towards the use of urine-derived fertilizers and will be testing and evaluating educational interventions.”
In addition to CEE’s Nancy Love, Krista Wigginton and Glen Daigger, University of Michigan personnel on the project include Associate Professor Rebecca Hardin, School of Natural Resources and Environment, and Professor Joseph Eisenberg, School of Public Health. CEE doctoral students Heather Goetsch and Andrea McFarland are deeply involved and helped write the grant application.
To learn more about urine-derived fertilizer, read “From Toilet t0 Table.”