Thursday, April 16, 2026
Researchers at the University of Manitoba and University of Regina have found widespread application of urea, a common farm fertilizer, can severely degrade water quality in the Canadian Prairies.
The researchers added urea to farm ponds to simulate the effects of agricultural fertilization in the southern Prairies, a University of Manitoba release said, and found urea increased growth of microscopic plants (algae) to levels 10 times higher than seen in other damaged ecosystems, such as Lake Winnipeg in Manitoba.
When compared with hundreds of similar water bodies across southern Saskatchewan, the study showed that nearly half of all Prairie lakes, wetlands, and reservoirs may be degraded by decades of urea use, the release said.
“Our findings help explain why surface waters around the world are experiencing rapid oxygen loss that kills fish, increases toxin exposure, and intensifies harmful algal blooms, pushing freshwaters to an ecological tipping point,” University of Manitoba assistant professor in biological sciences and lead author Cale Gushalak said.
Research paper co-author Peter Leavitt said urea accounts for over half of global fertilizer use and is considered safe because it’s non-toxic at concentrations ten times higher than those used in the research team’s experiment.
“The damaging effects of fertilizers are being increased by draining natural wetlands that are important biological filters, capturing runoff from farms before it enters rivers and lakes,” Leavitt said, adding wetlands mismanagement that excessively drains farmland and increases fertilizer export to freshwaters is the problem, not farmers.
Urea is still necessary due to global use, the researchers said, and can’t be substituted.
“Two-thirds of the world’s population is supported by urea and other nitrogen fertilizers—so we cannot, and should not, stop its use,” Gushulak said. “However, if the fertilizer is lost from the soils, and ends up degrading surface water, then everyone loses.”
The research paper was recently published it the internationally recognized publication Nature.
