Location: Soil Drainage Research
Project Number: 5080-13210-003-000-D
Project Type: In-House Appropriated
Start Date: Mar 17, 2022
End Date: Mar 16, 2027
Objective 1: Elucidate field and instream governing processes that control water quality and ecological response. Goal 1.1: Develop water table, soil moisture, and evapotranspiration measurement capacity within a subset of EOF network sites to better understand the water balance in tile drained landscapes. Hypothesis 1.2: The majority of observed edge-of-field P losses are attributable to old soil P rather than recently applied P fertilizers. Hypothesis 1.3: Preferential flow to subsurface tile drains are dominated by contributions from a relatively narrow band of the soil surface extending less than 1 m on either side of the drain. Objective 2: Quantify the response of ecosystem services (e.g., water quality, habitat, and biodiversity) to conservation practice implementation. Hypothesis 2.1: Implementation of conservation/aspirational practices (ASP) will significantly reduce edge-of-field surface and subsurface nutrient loss compared to business as usual (BAU) practices. Hypothesis 2.2: Including two or more conservation practices (stacking) will provide greater nutrient loss reductions compared to single practice implementation. Hypothesis 2.3: Improvements in soil health indicators will be associated with reduced edge-of-field nutrient losses. Hypothesis 2.4: Installation of instream inserts within an agricultural headwater stream will create riffle pool sequences that will increase instream habitat diversity and improve fish community integrity at the microhabitat spatial scale. Hypothesis 2.5: Installation of instream inserts in conjunction with channel rerouting and wetland creation will increase instream habitat diversity, improve fish community integrity, increase dissolved oxygen concentrations, and reduce downstream transport of nutrients. Hypothesis 2.6: Channelized agricultural headwater streams with greater instream habitat diversity will exhibit less nutrient concentrations and less within-season variability in nutrient concentrations and greater fish biodiversity and abundance. Objective 3: Contribute to LTAR network science, data synthesis, and model development through data collection and development/assessment of predictive tools. Hypothesis 3.1: Aspirational management systems (ASP) will improve soil health indicators compared to business-as-usual (BAU), but the degree of improvement will depend on site-specific factors. Goal 3.2: Identify the best environmental predictors of fish community structure in agricultural headwater streams in the Eastern Corn Belt LTAR node. Goal 3.3: Collect and synthesize data for Ohio high priority, agricultural tile drained watersheds.
Improved drainage, including subsurface tile and channelized streams, is required for sustainable agricultural crop production on an estimated 200 million ha of cropland worldwide. Another 425 million ha could benefit from improved drainage. The Midwest U.S. produces roughly 65% of the Nation’s annual corn and soybean production, largely as a result of artificial drainage. However, improved drainage has been linked to downstream water quality issues that include harmful algal blooms (e.g., Lake Erie and Gulf of Mexico) and hypoxia (e.g., Gulf of Mexico). Future climate predictions for the Midwest U.S. indicate more intense fall and spring storms and increasing temperatures that will heighten the importance of efficient drainage systems that maintain or improve ecosystem function and are in balance with new and/or enhanced production management practices, referred to as conservation/aspirational practices. Voluntary, incentive, and regulatory efforts have been applied to address agricultural nutrient loss and ecosystem function; yet, the problems persist. A combination of plot, field, and stream-scale research will be used to: isolate and understand the governing processes that control hydrological, water quality, and ecological responses; assess existing and novel management and conservation practices for their ability to reduce nutrient loss, enhance stream habitat and increase aquatic biodiversity; and synthesize the findings into improved simulation algorithms/scenarios for existing models and/or the development of new predictive tools. Successful completion of the proposed research will provide producers; certified crop advisors; extension specialists; researchers; drainage industry; conservationists; local, state, and federal action agencies; Western Lake Erie Basin (WLEB) and other watershed stakeholders; and decision/policy makers a better understanding of the governing controls and processes of nutrient dynamics in tile drained landscapes; quantitative assessments to develop and inform design, selection, and implementation of conservation practices; and enhance or improve the development and testing of prediction technologies.