Title: NWRF drainage
Location: Northwest Research and Demonstration Farm
Time Period: 2015-present
Research Team: Matt Helmers, John Sawyer, Emily Waring, and Carl Pederson
Project Description: The Northwest Research Farm (NWRF) is located near Sutherland, Iowa. Drainage research on the impacts of 4R N-management on crop production and nitrate-nitrogen (nitrate-N) loss began in 2015. Treatments include three N-management treatments (fall N, spring N, and split N) and one treatment with no N-fertilizer. The site includes 32 individually subsurface drained plots. Tile lines were installed in 2013 at a depth of 3.5 feet spaced 80 feet apart. The center tile line from each plot is pumped and monitored continuously for drainage volume with a flow meter (Figure 2 and 3). A flow-proportional sample is passively collected and subsamples are taken for nitrate-N, total-phosphorus (P) and total-reactive-phosphorus analysis. Soils are predominantly Marcus, Primghar and Galva, all silty clay loams. The 30-year average annual precipitation at NWRF is 30.7 inches. At NWRF, 4R N-management practices are examined for their impact on drainage N and P loss and crop yield:
Crops: Corn-soybean Management
Practices: Fall N-application with inhibitor, spring application, split N-application and no N-fertilizer application
Funders: This site was established with funding from the Iowa State University Department of Agronomy. Current research is funded by the 4R Research Fund and the Foundation for Food and Agriculture Research.
Disclaimer: This is an active research site, please contact the Northwest Research Farm staff prior to planning any site visits.