Iowa Nutrient Research Center Funds 11 New Water Quality Studies

wetland in farm field under cloudy sky
Among the new projects funded by the Iowa Nutrient Research Center is research studying materials that could be used in surface inlets draining farmed pothole-type depressions to filter phosphorus from drainage water. Photo by Nathaniel Lawrence, ISU.    

AMES, Iowa — The Iowa Nutrient Research Center at Iowa State University announces funding for 11 new water quality and nutrient management projects for 2020-2021.

“This round of projects represents over $1.3 million for water quality research,” said Matt Helmers, Iowa Nutrient Research Center director and professor of agricultural and biosystems engineering at Iowa State. “We are pleased that the projects reflect a number of the research priorities developed last year with a broad range of stakeholders, including farmers. These include supporting research on new nutrient-reduction technologies or cropping systems, developing better understanding of in-stream processes and examining potential unintended consequences of conservation practices.”

This is the Iowa Nutrient Research Center’s eighth year funding water quality research since it was created by the Iowa Legislature. The new projects will be led by researchers from Iowa State and the University of Iowa. Collaborators include USDA Agricultural Research Service, the Iowa Geological Survey and private landowners. Projects will 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.


  • Dam! Impacts of Beaver Dams on Surface and Groundwater Quality. Led by Billy Beck, Iowa State assistant professor, natural resource ecoloy and management, the project will explore key nutrient-removal processes associated with beaver dams and estimate their influence on watershed-scale nutrient loading within the agricultural Midwest.
  • Reducing Phosphorus Export through Farmed Pothole Surface Inlets with P Filters and Blind Inlets. Led by Amy Kaleita, Iowa State professor, agricultural and biosystems engineering, this project will investigate types of filtration materials that can be used in surface inlets to intercept and treat phosphorus before it moves out of the field through drainage systems. 
  • Soil Organic Carbon Controls on Nitrate Removal in Saturated Riparian Buffers. Led by Tom Isenhart, Iowa State professor, natural resource ecology and management, this project will evaluate the role of soil and vegetation characteristics in regulating nitrate loss within saturated buffers and use the data to refine site evaluation and design criteria.

Land Management

  • Completing Three Corn-Soybean Rotation Cycles for Ongoing Research on Impacts of Cover Crops on Phosphorus and Nitrogen Loss with Surface Runoff. Led by Antonio Mallarino, Iowa State professor, 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.  
  • Field Trials to Evaluate N Export from Perennial Groundcover Corn (PGC) Systems. Led by Raj Raman, Iowa State Morrill Professor, agricultural and biosystems engineering, the project will conduct field research to gain data on the impact of PGC systems on nitrogen loss.


  • Advanced Modeling of Soil Erosion, Sediment Delivery and Nutrient Export from Iowa Watersheds. Led by Matthew Streeter, research associate, IIHR Hydroscience and Engineering at the University of Iowa, this project will collect and analyze data on soil sedimentation and phosphorus-export from the Walnut Creek Watershed in Jasper County, Iowa. The data will be used to delineate sources of sediment-bound phosphorus and estimate phosphorus loss from the watershed.
  • Applying a New ACPF-Compatible Tool and Social Science to Explore the Role of Policy in Conservation Implementation in Iowa. Led by Emily Zimmerman, Iowa State assistant professor, agricultural and biosystems engineering, this project will demonstrate the use and utility of the Agricultural Conservation Planning Framework in support of different policy approaches designed to encourage implementation of conservation practices to meet Iowa Nutrient Reduction Strategy goals.
  • Bringing the Human into Precision Agriculture: What Farmers Need from Decision Support Systems to Meet Economic and Water Quality Goals. Led by Andy VanLoocke, Iowa State associate professor, agronomy, the project will explore how farmers and farm managers use data from precision agriculture systems to inform management decisions. The researchers will use their findings to develop a new precision agriculture tool.
  • Evaluating the Relation of Total Phosphorus to Turbidity During High Flow Events to Improve Quantification of Phosphorus Export from Iowa Rivers. Led by Keith Schilling, state geologist and director of the Iowa Geological Survey at the University of Iowa, the research team will gather and analyze data to improve quantification of phosphorus loads in major rivers as they leave the state.
  • IIHR Hydroscience and Engineering Work plan (2020-2021). Led by Chris Jones, researcher with IIHR-Hydroscience and Engineering at the University of Iowa, this project will continue to develop and aggregate data to be used by the Iowa Nutrient Research Center and others in support of enhanced nutrient management.

Nutrient Management

  • Furthering Our Understanding of the Role of Cereal Rye Allelochemicals in the Cereal Rye-Corn Production System. Led by Alison Robertson, Iowa State professor, plant pathology and microbiology, this project will study interactions between corn growth, allelochemicals secreted by cereal rye and seedling disease to inform best management practices for rye-corn production systems.  

The new grants bring the number of projects funded fully or partially by the center to 103, totaling more than $11 million invested in nutrient-related water quality research since 2013. 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.