Iowa Nutrient Research Center Funds New Set of Diverse Water Quality Studies

cattle grazing
A project to assess different types of forages and cover crops as cattle feed is among the 2019-2020 projects funded by the Iowa Nutrient Research Center. Photo courtesy of Iowa State University Extension and Outreach.  

Ames, IA – The Iowa Nutrient Research Center at Iowa State University has funded 16 new water quality and nutrient management projects for 2019-2020.

“I am pleased to announce the latest round of projects represent more than $2.03 million in funding for water quality research,” said Matt Helmers, Iowa Nutrient Research Center director and professor of agricultural and biosystems engineering at Iowa State. “The new grants bring the total number of projects funded fully or partially by the center to 92, a total of more than $10.7 million invested in nutrient-related water quality research since 2013.”

This is the Iowa Nutrient Research Center’s seventh year to fund water quality research since it was created by the Iowa Legislature. The new projects will be led by researchers from Iowa State, University of Iowa and University of Northern Iowa. They will also include private landowners and collaborators from the U.S. Department of Agriculture Agricultural Research Service, the Iowa Geological Survey, Iowa Beef Center, Iowa Learning Farms, Iowa Nutrient Research and Education Council, Iowa Soybean Association, Kirkwood Community College, The Nature Conservancy, the USDA Natural Resources and Conservation Service and several Iowa municipalities and watershed groups. Projects can extend for one to two years.

The new projects, listed below, fall into the following INRC categories: Edge-of-Field, Land Management, Multi-Objective and Nutrient Management.


  • Evaluating the Water Quality Benefits of Reconstructed Multi-purpose Oxbows. Led by Keith Schilling, state geologist and director of the Iowa Geological Survey at the University of Iowa, the research team will monitor four reconstructed oxbow sites (two tile-fed, two non-tile fed) and assess their effectiveness as a new conservation practice to reduce nitrate pollution and also improve aquatic habitat. 
  • Watershed-scale Phosphorus Inputs from Streambanks. Led by Peter Moore, adjunct assistant professor of natural resource ecology and management at Iowa State, this project will build on recent work supported by the INRC and others to develop more accurate and efficient estimates of streambank-derived phosphorus contributions to watersheds. 

Land Management

  • Evaluating the Potential for Drainageways to Serve as Test Sites for Innovative Grass Waterway Designs. Led by Keith Schilling, state geologist, the project will explore the potential to reconnect groundwater flowing through agricultural tiling systems with organic-rich soil deposits in drainageways, which could allow them to function as “natural bioreactors” on the landscape.   
  • Impacts of Cover Crops on Phosphorus and Nitrogen Loss with Surface Runoff. Led by Antonio P. Mallarino, Iowa State professor of agronomy, the project extends previous INRC research assessing the impacts of a winter cereal rye cover crop and two tillage systems on surface runoff of nutrients in a field testing high in phosphorus.
  • Improving Outcome Predictability, Multifunctionality and Cost-effectiveness of Nutrient Reducing Prairie Strips. Led by Justin Meissen, research and restoration program leader at the University of Northern Iowa’s Tallgrass Prairie Center, the project will seek to improve the implementation, functionality and cost-effectiveness of prairie contour strips for nutrient reduction, building on a prior INRC-funded study.
  • Interseeding Grass and Legume Cover Crops into Early Vegetative Stage Corn. Led by Mark Licht, Iowa State assistant professor of agronomy, the project will develop best management practices for interseeding cover crops into a corn cash crop, focusing on cover crop species, establishment timing and seeding method.
  • Perennial Turfgrass Cover Crops in Maize Production Systems. Led by Shuizhang Fei, professor of horticulture at Iowa State, this project will evaluate economic and environmental impacts of new perennial cover crop systems and assess their ability to reduce nutrient pollution.


  • Evaluating Rotations of Cover Crops and Summer Annual Forages for Yield, Nutritional Value, Effect on Soil Nutrient Profile and Economic Sustainability as Forage Resources for Beef Cattle. Led by Chris Clark, Iowa State Extension field specialist, the study will demonstrate and help develop best management practices for rotating winter cover crops and summer annuals to optimize forage production and improve soil and water quality.
  • IIHR Hydroscience and Engineering Workplan (2019-2020). Led by Chris Jones, researcher with IIHR-Hydroscience and Engineering at the University of Iowa, this project will continue to develop and aggregate the Iowa nutrient database and associated information on land use, weather, hydrological and water quality necessary to implement the Iowa Nutrient Reduction Strategy and support scientific understanding of nutrient flux at the watershed scale. This year’s work will include deploying one new sensor site for the Iowa Water Quality Information System (IWQIS), selected to support research by Iowa State faculty.
  • Increasing Farmer Engagement with Conservation Practices Through More Effective Communication Strategies. Led by Laura Witzling, assistant professor at Iowa State’s Greenlee School of Journalism and Mass Communication, the project will seek to identify more effective ways to engage farmer and landowner audiences – especially women and younger farmers -- in conservation practices aimed at reducing nutrient loss. 
  • Integrating Social and Biophysical Indicators of Nutrient Reduction Progress in Iowa Watershed Projects. Led by Iowa State research sociologist Laurie Nowatzke, the project will explore factors that impact adoption of nutrient reduction practices in smaller watershed project areas and build a dataset to analyze relationships between identified indicators and nutrient reduction programs and models. 
  • Linking Agricultural Practices to Water Quality Improvement: The Importance of Scale in Accurately Characterizing Nonpoint Source Nutrient Loads in Iowa Streams. Led by William Crumpton, Iowa State University professor of ecology, evolution and organismal biology, this project will examine the relationship between land use and stream nutrient concentrations and loads to improve understanding of factors including agricultural practices, hydrology and in-stream processes affect water quality. The project will refine landscape-scale models of nutrient delivery, using and expanding a network of monitoring sites in the Squaw Creek watershed north of Ames, Iowa.

Nutrient Management

  • Assessing the Effectiveness of Individual Versus Multiple Nutrient Reduction Practices on Water Quality and Economic Viability. The project, led by Sotirios Archontoulis, Iowa State associate professor of agronomy, will quantify the effectiveness of individual versus multiple/stacked nutrient loss reduction practices to identify suites of management practices that can improve water quality while maintaining or improving profitability. 
  • Investigating the Double-impact of Soil Health Promoting Practices on Water Quality. Led by Marshall McDaniel, ISU assistant professor of agronomy, this project aims to refine prediction of the economically optimum nitrogen rate, or EONR, using a new “combination” soil health test that uses CO2 Burst plus additional soil measurements at three research sites. Researchers also plan to develop a new economic tool that can reflect the double-impact of soil health on water quality and farm profits. 
  • Mitigating Reduced Corn Yields Following a Winter Rye Cover Crop: What Role Does Allelopathy Play? Led by Alison Robertson, professor of plant pathology at Iowa State, this project will investigate allelopathic compounds associated with the cover crop cereal rye and seek to understand if allelopathy explains why corn yields decrease in some fields where cereal rye is planted, but not in others. 
  • The Root of the Matter: Are Changes in Corn Root Morphology Responsible for Improved Yield and Higher Nitrogen Use Efficiency in Diversified Cropping Systems? Led by Matt Liebman, professor of agronomy at Iowa State, this project will investigate the potential of deeply rooted legume forage crops and small grains to simultaneously increase corn yield and nitrogen-use efficiency. Findings will be used to inform a widely used crop growth model, the Agricultural Production Systems sIMulator (APSIM).

Find more detail about these and past projects at

The Iowa Nutrient Research Center pursues science-based approaches to evaluating the performance of current and emerging nutrient management practices, providing recommendations on implementing the practices and developing new practices.