The purpose of the Iowa Nutrient Research Center is to pursue a science-based approach to nutrient management research through evaluating the performance of current and emerging nutrient management practices, and using an adaptive management framework for providing recommendations for the implementation of nutrient management practices and the development of new nutrient management practices. We continue to gain a better understanding of nutrient movement through the landscape in Iowa, and from that research, scientists funded by the center have made progress towards nutrient loss reduction.

Since 2013, the center has invested approximately $16.4 million in 136 nutrient-related water quality projects. More than 95 percent of the funding has gone directly to support research. Significant additional leveraging of center-supported projects comes through additional federal, state and private funding, 


Find highlights of INRC's recent activities and accomplishments in the Iowa Nutrient Research Center 2022 Annual Review (PDF). 

Find highlights of INRC's recent activities and accomplishments in the Iowa Nutrient Research Center 2021 Annual Review (PDF). 

Download the Iowa Nutrient Research Center 2020 Annual Review (PDF)

Download the Iowa Nutrient Research Center Accomplishments and Impacts, 2013-2019 (PDF)

Download the Iowa Nutrient Research Center Accomplishments and Impacts, 2013-2018 (PDF) 

Activities include

  • Leading nutrient-related water quality research collaboration across Iowa's three Regents Universities and agencies, including USDA, IDNR and IDALS.
  • Supporting 136 research projects in the following categories: Nutrient Management, Edge-of-Field, Land Management and Multi-Objective. 
  • Creating an innovative, interactive Iowa Water Quality Research map that features INRC projects and other water quality research around the state.  
  • Developed a Researcher Directory that highlights Iowa scientists engaged in nutrient reduction research.
  • Increasing communications about Iowa nutrient research through development of an upgraded website with additional online resources and expanding other outreach through regular news articles, a seminar series, research-related tours and networking, stakeholder meetings, videos and other activities.

Impacts include

Denitrifying bioreactors

  • Center research shows that this edge-of-field practice that filters tile drainage through woodchips can significantly reduce nitrogen pollution.
  • New research is investigating corn cobs and other carbon sources for bioreactors, which may be more economical and more effective at reducing other pollutants, including bacteria and phosphorus. 

Saturated riparian buffers 

  • The center continues to support research to fine-tune recommendations for this new technology with multiple benefits that center funds helped develop. 
  • The center helped develop federal and state conservation standards to make the practice eligible for available cost-share incentives. 

Multi-purpose Oxbows

  • The center funded important research documenting that multipurpose oxbows sited to intercept tile drainage can substantially reduce downstream nitrate loading in comparison with oxbows without contributions of tile drainage. 

Barriers to cover crops

  • The center has funded more than a dozen projects aimed at making cover crops more practical, profitable and effective as a way to improve water quality and soil health. 

Nutrient movement in the landscape

  • Center projects are helping identify the impact of stacked practices across paired watersheds.
  • Ongoing projects supported by INRC are aimed at better understanding nutrient movement and delivery in sub-watersheds.
  • Research on precision conservation and within-field nutrient management can help producers save money while protecting water quality on their farms and downstream. 

Prairie practices

  • Center projects are helping answer questions about how to successfully and cost-effectively establish prairie for multiple benefits.
  • The STRIPS project has pioneered a way to convert 10 percent of crop fields to native prairie strips, reducing soil loss and phosphorus export by up to 90 percent and nitrogen loss in surface runoff by 85 percent or more.