This project demonstrates and evaluates a nitrogen treatment system consisting of two practices: a two-stage ditch, and a bioreactor. The system was installed in September 2012 after 6 months of pre-construction monitoring of the existing ditch.

ditch

The Two-Stage Ditch was constructed by adding benches that serve as floodplains, stabilizing the channel and removing nutrients. Our research is determining impacts on water quality and fish communities, and the success of various plant types on the benches.

Timeline of two-stage ditch photos from construction to the present.

bioreactor A Bioreactor is a hole filled with wood chips that reduces nitrate in drainage water. The wood chips serve as a carbon source for denitrifying bacteria that turn the nitrate into harmless nitrogen gas. Our research is determining reduction in nitrate loads and impacts on phosphorus.

Timeline of bioreactor photos from construction to the present.

 

Practice Information and Preliminary Results

Two-stage Ditch (poster from June 2014 field day)
Vegetation mix used on the benches

Woodchip Bioreactor (poster from June 2014 field day)

Overview handout from June 2014 field day

Project Team

Dr. Laura Bowling, Agronomy, Project Director

Dr. Indrajeet Chaubey, Earth, Atmospheric, and Planetary Sciences and Agricultural and Biological Engineering

Dr. Reuben Goforth, Forestry and Natural Resources

Dr. Jane Frankenberger, Agricultural and Biological Engineering

Andi Hodaj, Agricultural and Biological Engineering

Erin Chichlowski, Agricultural and Biological Engineering

Amanda Brock, Agricultural and Biological Engineering

Purdue


To learn more, view the recording of the Webinar "Purdue's Two-Stage Ditch: What we've learned so far about what to plant and impact on nutrients" presented May 2014. This 1-hour presentation provides an overview of design and construction as well as monitoring results to date.

 

Ditch Location at Throckmorton Purdue Ag Center:

 

View Larger Map -- Address is 8343 U.S. 231, Lafayette, IN 47909.