Project Number: 3604-13000-008-00
Project Type: Appropriated

Start Date: Dec 22, 2006
End Date: Dec 21, 2011

Objective:
The overall project goal focuses on improving subsurface drainage water management systems (DWMS), particularly those employing controlled drainage practices, which will be used throughout the Midwest U.S., to provide both environmental and economic benefits. Accomplishing this goal requires an integrated research program that leads to enhanced controlled drainage operational strategies, improvement of DWMS design, development of flooding tolerant crop cultivars, and innovation in agricultural water treatment technologies. Specific objectives include: 1) Develop a knowledge base that will provide useful insight for improving controlled drainage operational strategies so as to maximize environmental and economic benefits. 2) Collect field data that will offer useful insight on proper DWMS design (particularly for controlled drainage systems), and then conduct a computer modeling investigation to determine the best controlled drainage design criteria and operational strategies that provide environmental and economic benefits. 3) Develop flooding stress tolerant soybean cultivars that are better adapted to Midwest U.S. DWMS wet soil conditions. 4) Develop constructed wetland and other water treatment technologies that can be integrated with DWMS to reduce nutrient and pesticide losses from cropland and turf environments.

Approach:
Conduct plot studies to quantify the subsurface drainage effects of three outlet control structure weir elevations and a scenario in which the outlet control structure weir height is gradually lowered. Conduct producer operated, field scale comparisons between open, unrestricted versus controlled subsurface drainage systems. Determine the effects of controlled drainage versus open, unrestricted drainage on surface runoff. Determine the soil quality effects of controlled drainage verses open, unrestricted drainage. Perform laboratory tests and field investigations to quantify processes affecting nitrate mobility in low permeability Midwest U.S. soils that typically require artificial subsurface drainage. Conduct plot studies to evaluate different subsurface drainage system infrastructure characteristics for the purpose of improving DWMS design criteria. Using data collected from different Midwest U.S. field locations, calibrate and verify computer models capable of simulating DWMS flow, water quality, and crop yield responses. If necessary, modify the computer program used to develop the computer models. Screen soybean cultivars of diverse origins for flooding stress tolerance and employ quantitative trait locus (QTL) mapping on the most promising cultivars in order to locate genes on the genetic linkage map that are responsible for flooding stress tolerance. Develop transgenic soybeans with improved flooding tolerance and then verify their flooding tolerance. For three constructed wetlands, assess present water treatment effectiveness along with vegetation/wildlife function and then evaluate, on the same basis, improvement modifications. Perform laboratory tests to screen novel filter materials for ability to remove nitrate and atrazine from drainage water. If an effective and efficient filter material is isolated in the laboratory, a field pilot test will follow. Evaluate the ability of commercially available filter materials to absorb or bind nutrients and pesticides present in tile drainage water from an urban turf environment.