By David Ostdiek
The Nebraska Environmental Trust has awarded a grant to construct a subsurface drip irrigation (SDI) system that uses feedlot effluent to irrigate crop fields. The practice will be evaluated as a potential means to better manage limited water resources, an ongoing research priority of the University of Nebraska.
The irrigation system is under construction at the university’s Mitchell Agricultural Laboratory, the site of the feedlot and research plots, says Xin Qiao, Extension irrigation and water management specialist and the principal investigator on the project. The Mitchell Lab is 5 miles north of the Panhandle Research and Extension Center in Scottsbluff.
Water that runs off the 105-pen feedlot into an effluent holding pond will be pumped through the SDI system to irrigate crop research fields, Qiao says. On some plots, air will be added to water by injecting it into the drip irrigation system to test its effect on water quality and crop yield.
The plots will be divided into two sections — one planted to sugarbeets and the other to corn — and 20 zones (10 in each section). Half of the zones will have air injected. Soil samples and water samples will be collected and tested for quality.
The Nebraska Environmental Trust grant provides $287,605 for the two-year project, which begins this year. The project is a collaboration between the Panhandle Center and work by Matteo D’Alessio and Chittaranjan Ray at the Nebraska Water Center.
Underground emitter tape was installed in the fields earlier this spring, and other equipment — including controllers and air injectors — is expected to be installed in early May. Mazzei, a California company that manufactures the injectors, is providing the injectors, Qiao says.
Reuse of wastewater is one option for making optimal use of limited water resources. In the North Platte River Basin, a moratorium on irrigation expansion and allocations on irrigation water have been in effect for years, with the goal of reducing streamflow depletions caused by irrigation water pumping. Wastewater could be an alternative source of irrigation water.
The outcome of this study may provide a best management practice to treat feedlot runoff and increase crop yield for corn and sugarbeets in western Nebraska, Qiao says.
Ostdiek is a communications specialist at the University of Nebraska Panhandle Research and Extension Center.