Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

•Event-based hysteresis behavior was examined in nested agricultural watersheds.•Factor analysis of hydro-meteorological data was compared to hysteresis behavior.•Sources and flow paths for nutrient delivery varied among water quality parameters.•Complex delivery mechanisms underscore the challenge of mitigating nutrient loss.•Conservation practices must address nutrient management and hydrologic connectivity.