RAPID: Using a drought-enhanced nitrate pulse to understand stream N retention and processing

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Nitrogen addition is a cornerstone of modern agriculture, but fertilization has impacted inland and coastal waters by increasing nitrogen concentrations, supporting excessive growth of aquatic plants, reducing oxygen concentrations, and triggering harmful algal blooms. Because of extreme drought in 2012, Midwestern soils have accumulated nitrogen that is expected to be driven into river networks by late summer or fall precipitation. This anticipated landscape-wide nitrogen pulse offers an immediate and unparalleled opportunity to record how nitrogen enters streams, and to quantify the transport, attenuation, and fate of nitrogen as it moves through stream networks. An existing stream monitoring network will be expanded and used to collect water samples during and after major precipitation events in fall 2012, taking advantage of a short-term opportunity to characterize nitrogen movement and processing in an agricultural landscape.Unintended consequences of fertilization are an increasingly important issue for resource managers. This project will add to our understanding of how nitrogen moves from agricultural lands into and through stream networks, and it will do so under climate conditions that are expected to be more common in the coming decades. Additionally, this project will support five early career scientists and a collaboration between the University of Nebraska-Lincoln, the University of Iowa, and Coe College. Inclusion of Coe College will provide opportunities for undergraduate research and mentoring of undergraduate students by faculty and graduate students.