NERF Drainage

Drainage well
Nutrient Management

Location:  Northeast Research and Demonstration Farm

Time Period: 1988-present

Research Team: Matt Helmers, Antonio Mallarino, Dan Andersen, Brian Dougherty, John Sawyer, Michelle Soupir, and Ramesh Kanwar

Project Description:  The Northeast Research and Demonstration Farm (NERF) has 36 1-acre research plots equipped with a drainage water monitoring system installed in 1988. Plots have 1-4 percent slope with Kenyon, Floyd, and Readlyn soils. Tile lines are installed at a depth of four feet spaced 95 feet apart. Management practices are evaluated for their impact on nitrate-N and dissolved phosphorus (P) loss and crop yield. To quantify the impact of these practices, researchers are monitoring subsurface drainage volume and collecting flow-proportional water samples for nitrate-N and dissolved P analysis. The 30-year average annual rainfall for NERF is 29.7 inches. The average tile drainage flow from 2001-2015 is 4.5 inches.

At NERF, multiple management practices have been examined for their impact on N and P loss and crop yield. 

Crops: Continuous corn, corn-soybean rotations, extended corn-oats-alfalfa rotation (1993-1998)

Management Practices: Rye cover crop, tillage/no-till, swine manure/urea ammonium nitrate (UAN), varied N application rates and timing, stover removal, nitrification inhibitor. 

Since 2016, treatments aim to study the impacts of N-management and in-field practices, including:

  1. Early fall vs. late fall vs. spring application of swine manure
  2. Conventional tillage vs. no-till
  3. Cereal rye cover crop vs. no cover crop
  4. Nitrification inhibitor
  5. One ton/acre gypsum application


Funders:  Support was provided in part by USDA-Agriculture Research Service, USDA-Cooperative State Research, Education and Extension Service, Leopold Center for Sustainable Agriculture, National Pork Producers Association, Iowa Agriculture and Home Economics Experiment Station, and Iowa State University College of Agriculture and Life Sciences. Support is provided in part by the Iowa Pork Producers Association and Calcium Products, Inc.

Disclaimer:  This is an active research site, please contact the research team prior to planning any site visits.