A recent study conducted by a team of Manitoba and Saskatchewan researchers reveals that a widely-used fertilizer essential for global food production can lead to the degradation of almost half of the freshwater bodies in the Canadian Prairies. Cale Gushulak, an assistant professor at the University of Manitoba’s biological sciences department and a participant in the study, highlights the reliance of about two-thirds of the world’s population on nitrogen-based fertilizers like urea for their agricultural needs. Despite this dependence, there has been limited research on the impact of urea on aquatic environments.
The research experiment involved the addition of urea to farm ponds in Saskatchewan to mimic the effects of agricultural fertilization in the southern Prairies. The results showed a significant increase in the growth of microscopic algae, leading to oxygen depletion in the ponds. Gushulak emphasizes the detrimental consequences when fertilizers enter water bodies, causing severe water-quality deterioration.
The study underscores the alarming trend of rapid oxygen depletion, fish mortality, heightened toxin exposure, and harmful algae blooms in surface waters, pushing many freshwater bodies in the region to an “ecological tipping point.” Analysis of numerous water bodies in southern Saskatchewan suggests that nearly half of the lakes, wetlands, and reservoirs in the Prairie region could be impacted by decades of urea usage.
Furthermore, Gushulak points out that agricultural areas in China and the United States face similar vulnerabilities to urea-related damage. While advocating for improved fertilizer technology and soil management practices to prevent fertilizer runoff into water bodies, he discourages the outright cessation of fertilizer use.
Asim Biswas, a professor at the University of Guelph, acknowledges the significance of the study but notes the need to consider how urea interacts with existing phosphorus levels in the ecosystem. He cautions against overstating the impact of urea on entire ecosystems and emphasizes the importance of understanding phosphorus dynamics in shallow water bodies.
Gushulak highlights the prevalence of high phosphorus levels in most Prairie water bodies, making them susceptible to urea contamination. He stresses that despite not all water bodies worldwide being equally affected, many agricultural regions with fertile lowlands and shallow water bodies are at risk.
The findings challenge the perception of Canada as a water-rich country, with Gushulak pointing out that the available freshwater is often inaccessible or located in remote areas. Concerns about declining water quality and availability due to urea contamination are compounded by anticipated climate changes in the Prairies, which could further impact water security in the region.
In conclusion, the study sheds light on the urgent need for sustainable agricultural practices to safeguard freshwater resources from the detrimental effects of urea contamination.