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ARS Home » Midwest Area » Ames, Iowa » National Laboratory for Agriculture and The Environment » Agroecosystems Management Research » Research » Publications at this Location » Publication #404748
Research Project: Sustainable and Resilient Cropping Systems for Midwestern Landscapes

Location: Agroecosystems Management Research

Title: Streambank erosion and phosphorus loading to surface waters: Knowns, unknowns, and implications for nutrient loss reduction research and policy

Author
item MARGENOT, ANDREW - University Of Illinois
item ZHOU, SHENGNAN - University Of Illinois
item MCDOWELL, RICHARD - Lincoln University - New Zealand
item HEBERT, THOMAS - Bayard Ridge Group Llc
item FOX, GAREY - North Carolina State University
item SCHILLING, KEITH - Iowa Geological Survey
item RICHMOND, SHAWN - Iowa Farm Bureau Federation
item Kovar, John
item WICKRAMARATHNE, NIRANGA - University Of Illinois
item LEMKE, DEAN - Lemke Engineering & Environmental Services
item BOOMER, KATHY - Foundation For Food And Agriculture Research

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2023
Publication Date: 10/15/2023
Citation: Margenot, A.J., Zhou, S., Mcdowell, R., Hebert, T., Fox, G., Schilling, K.E., Richmond, S., Kovar, J.L., Wickramarathne, N., Lemke, D., Boomer, K., et al. 2023. Streambank erosion and phosphorus loading to surface waters: Knowns, unknowns, and implications for nutrient loss reduction research and policy. Journal of Environmental Quality. 52(6):1063-1079. https://doi.org/10.1002/jeq2.20514.
DOI: https://doi.org/10.1002/jeq2.20514

Interpretive Summary: Losses of phosphorus (P) from agricultural lands represent a major cause of water quality impairment within Iowa and elsewhere in the U.S. Producers and land managers have made progress over the last several decades in reducing soil-bound P losses from agricultural lands to receiving waters via soil erosion. However, there is a growing body of evidence that much of the sediment and P delivered to the surface waters from agricultural landscapes originates from streambanks. In this review, the results of current research efforts that focus on streambank erosion and its contributions to P loading of surface waters were reviewed and summarized. This review overviewed the knowns and unknowns, proposed next steps to understand streambank erosion contribution to P export budgets, and discussed implications of the science of streambank erosion for policy and nutrient loss reduction strategies. Despite limitations in the analysis, an improved understanding of streambank P contributions will help natural resource managers make improved recommendations for effective soil and water conservation practices that best reduce P loading to streams and rivers.

Technical Abstract: To monitor and meet water quality objectives, it is necessary to understand and quantify the contribution of non-point sources to total phosphorus (P) loading to surface waters. However, the contribution of streambank erosion to surface water P loads remains unclear and is typically unaccounted for in many nutrient loading assessments and policies. As a result, agricultural contributions of P are overestimated, and a potentially manageable non-point source of P is missed in strategies to reduce loads. In this perspective, we reviewed and synthesized the results of a special symposium at the 2022 ASA-CSSA-SSSA annual meeting in Baltimore, MD, which focused on streambank erosion and its contributions to P loading of surface waters. Based on discussions among interdisciplinary researchers and policy experts, we overviewed the knowns and unknowns, proposed next steps to understand streambank erosion contribution to P export budgets, and discussed implications of the science of streambank erosion for policy and nutrient loss reduction strategies.