DRAINAGE WATER MANAGEMENT FOR MIDWESTERN ROW CROP

AGRICULTURE

DWM PARTNER FORUM IIJUNE 15, 2011

WAYNE HONEYCUTTUSDA-NRCS

THE PROJECT

• Conservation Innovation Grant• Awarded FY-2006• Grantee: Agricultural Drainage

Management Coalition• Focus area: Ohio, Indiana, Illinois, Iowa,

& Minnesota

Collaborators

• Ohio State University • Purdue University • University of Illinois • Iowa State University • Minnesota Dept. of Agriculture• University of Minnesota• USDA-ARS (IA, OH)

OBJECTIVE

To demonstrate the benefits of DWM on water quality, soil quality, and farm economics

Water Control Structure Installation

Water Control Structurewith data transmission

Subsurface Drains in the 48-States

Five-State CIG Plot Locations

METHODS

• Twenty paired plots (four in each state) compared managed drainage with conventional drainage in fields with similar soils, subsurface drainage systems, yields, and management histories.

• Most sites were on private farmland, with plots planted using the same corn or soybean varieties, and treated with the same fertilizers and cultural practices

PAIRED PLOT EXAMPLE

METHODS

• All sites, except one, were retrofitted subsurface drainage systems, with manual water control structures

• Managed drainage systems were controlled by the producers

• Data was transmitted and monitored through the internet

MEASUREMENTS• Water flow rates from subsurface drains • Nitrate in water from subsurface drains (at

least weekly) • Precipitation• Crop yields• Timing of producer management • Production costs

RESULTS - Yield

• Crop yields were increased as high as 20 percent, and decreased as low as 12 percent

• 60 percent of annual comparisons had increased yields, and 40 percent had decreased yields

• Five-State average yield increase = 1.3 percent

RESULTS• Drainage Water Management reduced drainage outflow

and nitrate loads by up to 90 % (average = 35 %) • No significant differences in nitrate concentrations were

observed

RESULTS - Economics• DWM components add only 10 percent to total cost of

redraining

• Cost of Water Control Structures for CIG Subsurface Drainage System Retrofits

Pipe Diameter Cost of Retrofit Cost for 20-acre Zone (in.) ($/each) ($/acre)

6 1,308 65 8 1,428 71 10 1,536 77 12 1,764 88

RESULTS - Outreach

–Field days (22)–Training sessions (21)–Workshops (43)–Technical conferences (67)–Periodicals/brochures (7)–Producer surveys (1)–Radio/TV interviews (2)

Control Structure Installation at Field Day

RECOMMENDATIONS

• DWM retrofits feasible on field slopes of 0.5 percent or less (potential 10M acres in US)

• DWM with contour redraining feasible on field slopes of 2.0 percent or less (potential 60M acres in US)

CONCLUSIONS

Negligible impacts on yield

Very substantial environmental impacts

Project Recommendations

• More information on deep and lateral seepage, including denitrification potential

• Further evaluation of economics

Five-State CIG Impacts

• NRCS Conservation Practice Standard “Drainage Water Management ” (554) was revised in 2008 to include timeframe for manage drainage water

• NRCS Practice Payment Schedules were

revised in 2011 to improve regional consistency for “Drainage Water Management Plan” (130) and “Drainage Water Management” (554)

Continuing Efforts

• Collaborators plan to publish State-specific CIG data and results, in peer-reviewed journal (2012)

• NRCS will utilize soils and crop input files from

CIG to start building DRAINMOD database in the Five States (2012)

Further Information

• ADMC website link to Five-State CIG report: http://www.admcoalition.com/

stateresources.html • NRCS website link to CIG program:

http://www.nrcs.usda.gov/technical/cig/index.html

Five-State CIG Results Managed v. Conventional Drainage

2007-2009

Drainage Nitrate Crop Outflow Reduction Load Reduction Yield IncreaseState (%) (%) (%)

Ohio 60.9 53.4 4.9Indiana 7.0 0.1 1.4Illinois 58.3 68.0 1.3Iowa 39.4 38.8 0.3Minnesota 22.3 36.1 -0.5

All 34.9 34.4 1.3

Five-State CIG ResultsRegional DWM Control Plans