Leopold Center for Sustainable Agriculture

Completed Competitive Grant

Evaluating denitrifying bioreactors for edge-of-field nitrogen management in Iowa's tile-drained landsacpes

Project ID: E2009-11

Abstract

Bioreactors show significant potential for removing nitrate from Iowa’s drained fields. The investigators tested the design and management of bioreactors to see what factors can make the bioreactors operate most efficiently, and how that performance compares to other drainage water quality improvement practices.

Key Question: How can we design and operate bioreactors to optimize their nitrate removal under field conditions?

Findings: This was answered by evaluating pilot- and field-scale bioreactors to evaluate design factors (e.g., cross-sectional bioreactor shape, bioreactor length to width ratio, bioreactor volume, and retention time) and environmental factors in the field (e.g., temperature, flow rates, nitrate concentrations).

Lead investigator: Matt Helmers, ISU Agricultural and Biosystems Engineering

Co-Investigator(s):

Alok Bhandari, Kansas State University (formerly at Iowa State University)

Year of grant completion: 2012

This competitive grant project was part of the Leopold Center's Ecology Initiative.

Topics: Corn-soybean cropping systems, Economic and environmental impacts, Water quality, quantity and management