The need to produce more food, feed, fiber, and fuel with less water now looms as perhaps the greatest challenge ever faced by farmers worldwide. Our ability to meet this challenge may well determine not only our overall quality of life, but also our very survival in the future. Developing and adopting enhanced irrigation and crop management technologies that achieve greater water-use efficiencies is essential.
What Has ANR Done?
For the past several years, a team of researchers, farmers, and private sector partners has been working at the University of California West Side Research and Extension Center in Five Points, Calif. to develop enhanced water and crop management systems for a range of crops commonly produced in the central San Joaquin Valley. This work has focused on the coupling of advanced sustainability technologies (such as precision overhead and subsurface drip irrigation systems) with strip-till and no-till planting to achieve cheaper and more sustainable systems.
The use of overhead irrigation (sometimes called "mechanized" irrigation) is not new in many parts of the world. Overhead pivot irrigation is widely used in the Pacific Northwest, the Great Plains, and the southeast U.S. as well as in many other places around the world. It is the most widely used irrigation system in the U.S. and has been successfully adopted in those regions for decades, but it is not widely used in California.
The Five Points research team is working to couple the proven benefits of overhead irrigation, including labor, cost and water savings, with additional benefits derived from preserving high amounts of surface crop residues. "Our goal," says UC Davis researcher Jeff Mitchell, "is to follow in the steps of legendary South Dakota State University researcher Dwayne Beck, and the no-till farmers he works with, to have crops use water more efficiently."
Coupling precision overhead irrigation with no-tillage increases efficiencies
Working with colleagues at Valley Irrigation in Omaha, Neb., the California team found that irrigation water application uniformity for the overhead system is 93 percent. This excellent level of application uniformity allows for less water use to meet irrigation demand than systems that are less uniform, such as surface or gravity flow furrow irrigation. In addition, the team showed that 13 percent (4 inches) of soil water evaporation can be saved in the soil during a typical summer season when a thick matte of residues is on the soil surface. This research shows the potential for California farmers to reduce water use and evaporation by combining overhead irrigation and no-till practices.
Department of Plant Sciences, UC Davis, Department of Land, Air and Water Resources, Fresno County Cooperative Extension
1. Jeff Mitchell, Department of Plant Sciences, UC Davis
2. Wes Wallender, Department of Land, Air and Water Resources, UC Davis
3. Will Horwath, Department of Land, Air and Water Resources, UC Davis
4. Dan Munk, Fresno County Cooperative Extension