A recent study conducted by a team of researchers from Manitoba and Saskatchewan reveals that a widely-used fertilizer, crucial for global food production, could harm almost half of the freshwater bodies in the Canadian Prairies. Despite this, an expert suggests that the study may be exaggerating the issue.
Cale Gushulak, an assistant professor at the University of Manitoba, highlights that a significant portion of the world’s population relies on nitrogen-based fertilizers like urea for agriculture. However, there has been limited research on the impact of urea on aquatic environments.
The researchers conducted an experiment by adding urea to farm ponds in Saskatchewan to mimic the effects of fertilizer use in the southern Prairies. They observed a substantial increase in algae growth, leading to oxygen depletion in the ponds, resulting in adverse water quality.
Gushulak emphasizes that when fertilizers seep into water bodies instead of remaining on land for crop growth, it triggers severe water quality deterioration. Given the widespread use of urea globally, this issue could have far-reaching consequences.
The study findings suggest that excessive algae growth, oxygen depletion, fish mortality, toxin exposure, and harmful algae blooms are accelerating in surface waters, pushing these bodies towards an environmental tipping point. The research indicates that nearly half of Prairie lakes, wetlands, and reservoirs may have suffered degradation due to decades of urea application.
Moreover, the study reveals that agricultural regions in countries like China and the United States face similar risks from urea use. Gushulak advocates for enhancing fertilizer technology and soil management practices to prevent urea from entering freshwater systems.
Asim Biswas, a professor at the University of Guelph, acknowledges the study’s significance but cautions that urea’s interaction with existing phosphorus levels in water bodies must be considered. He highlights that shallow water bodies with high phosphorus content are more susceptible to urea impact.
Gushulak notes that while not all water bodies worldwide will experience the extreme effects of urea, many agricultural areas with fertile lowlands and shallow water bodies are at risk. The study challenges the perception of Canada as a nation abundant in freshwater, emphasizing the urgency of addressing water quality issues.
Continued infiltration of urea into freshwater bodies could exacerbate water quality problems and increase water scarcity, especially as climate changes affect water levels. Gushulak stresses the need for sustainable practices to safeguard water resources for future generations.
