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ARS Home » Midwest Area » Columbus, Ohio » Soil Drainage Research » Research » Publications at this Location » Publication #389444
Research Project: Agricultural Water Management in Poorly Drained Midwestern Agroecosystems

Location: Soil Drainage Research

Title: A retrospective analysis of climate and land management drivers of nutrient export from the western Lake Erie watershed: 1980-2019

Author
item APOSTEL, ANNA - The Ohio State University
item KALCIC, MARGARET - The Ohio State University
item LOGSDON-MUENICH, REBECCA - Arizona State University
item King, Kevin
item MARTIN, JAY - The Ohio State University
item SCAVIA, DON - University Of Michigan

Submitted to: Aquatic Ecosystem Health & Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/9/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Water quality, specifically harmful algal blooms, continue to plague the Western Basin of Lake Erie. Understanding and being able to predict the impact and importance of climate and management on hydrology and nutrient transport is critical to identifying management practices that can be implemented to address the water quality issue. Watershed data collected between 1980 and 2014 was used to populate the Soil and Water Assessment Tool and the tool was used to show that climate factors were more important for hydrology and dissolved phosphorus losses while management, specifically reduction in tillage had a greater influence on total phosphorus. The ability to represent historic water quality changes provides greater utility and confidence in model predictions and assessment of proposed practices which is critical for watershed educators, planners and policy makers.

Technical Abstract: The return of harmful algal blooms (HAB) to western Lake Erie has increased focus on managing nutrient loading. Increased dissolved reactive phosphorus (DRP) loads over the last twenty years is suspected to be a primary cause of the recurrence and severity of these blooms. Management efforts to reverse this trend are difficult to develop due to uncertainty regarding whether climate or which land management factors are responsible. We used refined models of the Maumee River Watershed to investigate changes in climate and land management between 1980 and 2014, to identify key factors driving the DRP increases and changes in other nutrients that are important in the rise in algal biomass and toxicity. We found that the role of dominant driver varied between climate and land management among discharge and nutrients. Climate dominated discharge, DRP load, and nitrogen concentrations, while management drove a larger fraction of phosphorus concentration and total phosphorus (TP) load changes. Among the land management changes examined, the rising adoption of minimal- and no-tillage strategies had the greatest impact on nutrient trends among other management changes, leading to reductions in TP, total nitrogen, and nitrate, as well as increases in DRP. We posit that a better understanding of the water quality impacts of past land management enables models to more accurately assess the impacts of potential future management changes.