Nitrogen dynamics and nitrogen‐to‐phosphorus stoichiometry in cold region agricultural streams

Cold agricultural regions are getting warmer and experiencing shifts in precipitation patterns, which affect hydrological transport of nutrients through reduced snowpack higher annual proportions summer rainfall. Previous work has demonstrated that the timing phosphorus (P) concentrations is regionally coherent streams northern Great Plains, suggesting a common climatic driver. There been less investigation into patterns stream nitrogen (N), despite its importance for water quality. Using high-frequency quality data collected over 6 yr from three southern Manitoba streams, goal this research was to investigate seasonal N P resultant impacts these on N/P stoichiometry. In spring, high inorganic were associated with snowmelt runoff, while dominated by organic forms; remained consistently low summer, increased biological transformation removal. Relationships between concentration discharge showed generally weak model fits (r2 values significant relationships ranging .33 .48), strength direction differed among seasons, forms N. Dissolved strongly dissolved carbon. Nitrogen-to-phosphorus ratios varied but significantly lower during storm events (p < .0001). These results suggest climate-driven temperature may negatively downstream region.