Location: Soil Drainage Research
Title: Summary update of crop yield results from three wetland reservoir subirrigation systems in northwest Ohio Authors
|Clevenger, William -|
|Labarge, Gregory -|
|Prill, Gary -|
|Czartoski, Bernard -|
|Brown, Larry -|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 26, 2014
Publication Date: N/A
Interpretive Summary: Achieving global food security will require innovative technologies to assure efficient utilization of resources and adaptation to climate change. The Midwest US is a major producer of food and feed, and this region is subject to both excess and deficit water conditions. Drainage of the soils in this region is a requirement for efficient crop production. Climate trends indicate this region is becoming wetter and warmer signaling that the need for drainage will increase, but the probability of annual dry periods also will increase. Drainage water recycling, by capturing and storing excess water that is removed for efficient farming and then applying this water by subirrigation to meet crop needs during deficit water periods, is a viable win-win solution, This study evaluated the crop yields from subirrigated fields receiving recycled drainage water compared to fields without subirrigation. Subirrigated fields had respectively larger corn and soybean yields of 28.7% and 25.2% during dry growing seasons, 14.1% and 6.9% during near average or wet growing seasons, and 19.1% and 12.1% overall. This finding is important for producers and policy makers.
Technical Abstract: Wetland Reservoir Subirrigation Systems (WRSIS) are innovative agricultural water management and recycling systems comprised of three main components; a constructed wetland, a water storage reservoir, and cropland containing subsurface drainage pipe systems. Surface runoff and subsurface drainage from cropland are diverted to a constructed treatment wetland to partially remove nitrogen nutrients and suspended sediment. Water in the wetland is then routed to a storage reservoir and held there until needed during the growing season for subirrigation. With subirrigation, water from the reservoir is added directly to some of the cropland subsurface drainage pipe systems in order to irrigate the crops through the root zone. Three WRSIS were installed in northwest Ohio, USA; one in Defiance County, one in Fulton County, and one in Van Wert County. These three sites were operated/monitored from 1996 through 2008. Potential WRSIS benefits include; (1) reduced offsite release of nitrogen nutrients and suspended sediment, (2) additional wetland vegetation and wildlife habitat, and (3) enhanced crop yields. With respect to crop production at all three sites combined, the subirrigated fields within WRSIS, as compared to fields with conventional, unrestricted subsurface drainage, were found to have respectively larger corn and soybean yields of 28.7% and 25.2% during dry growing seasons, 14.1% and 6.9% during near average or wet growing seasons, and 19.1% and 12.1% overall. However, subirrigated field crop yield results varied substantially between the sites, and the greatest corn/soybean production increases were found at the Fulton County WRSIS, with the Van Wert County WRSIS next, followed by the Defiance County WRSIS. At the Defiance County WRSIS, which had high clay content, low hydraulic conductivity soils, a shorter subirrigated field drain line spacing distance (half of what is typical for subirrigation) was found to improve the yield of corn, but not soybeans. This study on the whole indicates that WRSIS can provide significant crop yield benefits, especially for dry growing seasons.