Drainage in Iowa and Opportunities for Drainage Design to Incorporate Economic
and Environmental Aspects
Matthew Helmers
Situation
Subsurface drainage has allowed for excellent
agricultural production within many areas of Iowa. However, these systems
allow for short-circuiting of some agricultural pollutants, specifically
nitrate-nitrogen, to nearby surface water bodies. This has contributed to
local and regional water quality concerns including hypoxia in the Gulf of
Mexico. Future system designs will need to incorporate not only economic
but also the environmental aspects of drainage.
Objective
Provide information about the benefits
and drawbacks of subsurface drainage systems and how drainage-system design
and management can include economic and environmental aspects.
Activities/Outputs
- The University of Minnesota Extension coordinated the Iowa-Minnesota
Drainage Research Forum in which 110 individuals participated. Attendees
included producers, drainage contractors, university personnel, and agency
representatives from both Iowa and Minnesota. In addition, there were attendees
from Canada.
- In January, a presentation of drainage activities was given at the Iowa
Land Improvement Contractors Annual meeting.
- Drainage design that considers economics and the environment was presented
at the Crop Advantage Series meetings in Cedar Rapids, Mount Pleasant,
and Atlantic and the North Central Iowa Crop and Land Stewardship Clinic
in Iowa Falls.
- Seventy-five individuals including producers, drainage contractors, university
personnel, and agency representatives coordinated an Agricultural Drainage
and Water Quality Field Day at the Gilmore City Drainage Research and Demonstration
Facility.
Impact/Outcomes
- One outcome from this programming was that stakeholders received information
about emerging drainage design considerations that take into account the
environmental and economic aspects of drainage.
- Of the 40 evaluations that were received at the Drainage Research Forum,
39 indicated the forum was worth their time. Responses included “good
public-private balance,” “integrity of the information,” “forward
looking, thinking information,” and “practical application
of topics discussed.”
- Evaluations from the Crop Advantage Series meetings indicated attendees
learned about effective tile spacing and tiling cost.
- Based on long-term simulations, narrower drain spacing may not always
produce greater yields but will produce greater subsurface drainage volumes,
which could be detrimental to the environment. As a result, if producers
design for long-term maximum yields they may be able to use wider drain
spacing and save on the order of $200 per acre when installing a drainage
system. This could reduce the investment from approximately $600 to $400
per acre, providing both economic and environmental benefits. On more than
one occasion producers indicated they would think about this when designing
and installing a drainage system.
2005
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Page last updated:
July 9, 2006
Page maintained by Linda Schultz, lschultz@iastate.edu
