This project builds on the collaborative model established through our long-term work in SDW and developing partnerships in KDW. It leverages a significant monetary investment through the USDA-RCPP program. Our partners include the Soil and Water Conservation Districts (SWCDs) and local producers/landowners in each of the two watersheds located in Kosciusko and Jasper/Newton/Benton Counties, their respective County Surveyors, the Indiana Chapter of The Nature Conservancy (TNC), The US Geological Survey (USGS), and researchers at the University of Notre Dame (ND), Indiana University (IU), and Iowa State University (ISU). We remain committed to sustained outreach activities to educate stakeholders about the benefits of pairing cover crops with the two-stage ditch at the watershed scale. We continue to host multiple stakeholder meetings within and across watersheds to coordinate monitoring and implementation efforts, and to disseminate our ongoing results. We are disseminating our project results widely by participating in a variety of outreach events at the local, national and international level. Since the start of the IWI RCPP project (May 2015), we have presented and/or participated in 24 agricultural/field day events, given 64 conference presentations and hosted 9 watershed tours. In June 2017, PI Jennifer Tank organized and chaired a special session on “Quantifying water quality outcomes of watershed-scale conservation projects” at the annual conference of the University Council in Water Resources (UCOWR) in Colorado; all of the students participating in the IWI RCPP presented their research and had an opportunity to interact with invited speakers from around the nation. In September 2017, we also hosted a tour for 30+ NRCS Engineers at the SDW after the recent implementation of an addition 2.4 miles of two-stage ditch, making SDW the longest continuous two-stage in the world at 2.9 miles in total. Team members also gave invited talks at the AGU Chapman Conference in Puerto Rico, and at the 2017 ASLO Aquatic Sciences Meeting in Hawaii. We also continue to maintain our online presence via our website and social media accounts which provide a place to share results, updates, and project resources including one-page data summaries. We continue to use these opportunities to discuss the benefits of cover crops and the two-stage ditch on water quality/quantity and soil health (Objectives 1 and 2) and results from model parameterization and economic analysis (Objectives 3 and 4).
Two new manuscripts describing our work were recently published: (1) a manuscript describing our work on creating a new two-stage ditch module for the SWAT model (using data from this project for calibration) is now available in Ecological Engineering, and (2) a manuscript (led by former PhD student Brittany Hanrahan) the first 4 years of stream and tile drain results from the SDW is now available in Agriculture, Ecosystem & Environment, which is a high impact journal with an international audience.
• S.F. Christopher, J.L. Tank, U.H. Mahl, H Yen, J.G. Arnold, M.T. Trentman, S.P. Sowa, M.E. Herbert, J.A. Ross, M.J. White, T.V. Royer. Modeling nutrient removal using watershed-scale implementation of the two-stage ditch. Ecological Engineering 108 (B):358-369.
• Winter cover crops reduce nitrate loss in an agricultural watershed in the central U.S. 2018. B.R.Hanrahan, J.L.Tank, S.F.Christopher, U.H.Mahl, M.T.Trentman, T.V.Royer. Agriculture, Ecosystems & Environment. Volume 265, 1 October 2018, Pages 513-523. https://doi.org/10.1016/j.agee.2018.07.004
In addition, Sheila Christopher is working on a manuscript describing the changes we have measured in watershed soils as a result of cover crop planting and Brittany Hanrahan is working on a manuscript describing the changes we have measured in phosphorus export at field and watershed scales. We continue to have open dialogue between the County Soil and Water Conservation Districts (in each watershed), the Nature Conservancy, and the University of Notre Dame, Indiana University and Iowa State University researchers, which is essential for the success of conservation practice implementation and data collection.