Production Ag: Sub-surface Irrigation Study Findings
The Kansas State University Research Center in Colby, Kansas, has been studying ways to use precious groundwater more efficiently. Subsurface drip irrigation has been tested for 25 years according to the High Plains Journal.
Freddie Lamm, irrigation engineer, said the SDI system is relatively expensive to install and still relatively new to Kansas. He went on to say to be cost competitive with a center pivot irrigation system the SDI system needs to last for a minimum of 10 to 15 years.
After 25 years, Lamm said all 23 plots in his research study are within plus or minus 7 percent of their original flow rates. The average corn yield on those plots over 24 seasons was 231 bushels per acre. Even in the drought year of 2012, they averaged 251 bushels per acre. Lamm said in four different studies from 1989 to 2004, they found that yields plateaued at 80 percent of full irrigation.
SDI can conserve water by eliminating irrigation runoff, and because it is below the soil surface, water evaporation is greatly reduced. Another advantage is the soil’s surface is dry, so rain can be absorbed.
Researchers have also experimented with pumping livestock wastewater through the system, and with some adaptations, were successful. Some of the added benefits to wastewater use are: no runoff, reduced human contact, less odor, and saving of fresh water.
“The system itself cannot save water, whether it is furrow irrigation, center pivot, or SDI,” Lamm said. “It takes a human decision and human management to save water.”
For more information on SDI research at the Northwest Research Station, go to http://www.ksre.ksu.edu/sdi/.