An assessment of nutrient dynamics in streambank soils of the Lower Little Bow River in southern Alberta using ion exchange membranes

Abstract

Nutrient dynamics in streambanks may impact nutrient movement to water, and may be influenced by cattle activity, river water level fluctuations, and time. Our objective was to determine the influence of these factors on nutrient (NO3-N, P, S, Fe, Mn, Cu, Zn, Ca, Mg) dynamics in streambanks along the Lower Little Bow River in southern Alberta using Plant Root Simulator or PRS® probes. Three experiments were conducted from 2012 to 2015. In the first experiment, few significant (P ≤ 0.05) effects were found among three reaches varying in cattle impact except for Fe and Mn, which generally increased with increasing cattle impact. In the second experiment (probe placement), adsorption of P, Fe, Mn, S, Ca, and Mg was significantly greater for submerged than exposed streambanks, and the opposite trend occurred for Cu and Zn. In the third experiment on the influence of probe burial periods from 0.2 to 14 days, maximum nutrient adsorption generally occurred within 1 to 7 days, and S adsorption showed an exponential increase with time. Overall, few cattle impact effects were found on nutrient dynamics, certain nutrients were greater in submerged than exposed banks, and 7-day burial of PRS probes was sufficient to assess nutrient dynamics.