What is in this article?:
- Irrigation management and scheduling a balancing act
- Available Resources
- The proper timing, frequency and amount of irrigation depend on a number of factors that must be taken into consideration.
- To ensure almond trees are neither over- nor under-watered requires diligent management and monitoring of these variables.
Professor Ken Shackel (left) inspects a psychrometer for automatic measurement of almond tree water stress, while graduate student Jessica Myles (right) takes measurements using a hand-pump version of the pressure chamber.
Fortunately, there are a number of resources for almond growers to use in planning and executing an irrigation management and scheduling program. In addition, research funded by the Almond Board continues to refine and improve upon this knowledge.
One resource is the California Almond Sustainability Program (CASP), which offers growers the opportunity to assess their operations and practices, benchmark them against others, and determine areas of improvement. Go to the Almond Board website (www.AlmondBoard.com/Growers) and click on the Sustainability tab. In addition to a self-assessment, the irrigation management module is rich with valuable references and tutorials (e.g., Irrigation Consumer Bill of Rights, Irrigation Scheduling 101) from UC, Cal Poly San Luis Obispo, and CSU Fresno. It is certainly worth reviewing. Even better, if you have not participated in a self-assessment workshop, you can do so by contacting Kendall Barton at (209) 343-3245 or firstname.lastname@example.org
Current Research Seeks Refinements
Recent research funded by the ABC and others, and led by UC Farm Advisors Blake Sanden, Dan Monk and Allan Fulton, is updating the almond crop coefficients ( Kc ) values used for tracking almond evapotranspiration. These updates will be available for use in the 2013 crop year.
Currently, the pressure chamber is the field production standard for measurement of tree water status, but alternatives are being investigated because use of the pressure chamber is labor intensive, time consuming, and not amenable to automation. To this end, Ken Shackel and UC farm Advisor David Doll are investigating a number of alternatives. The one which shows the most promise is a commercially available device called a psychrometer, which is sealed against a leaf or stem to measure water stress. This has the advantage of taking automated measurements, but the technology is still in the development phase.
Another alternative includes remote sensing (e.g., aerial overflights, satellites) combined with ground-level sensing. Sensing leaf temperature using infrared (IR) sensors is showing potential as a tool for irrigation management by determining plant water status. Mounting IR sensors along with other tools on a “mobile platform” to detect water status/stress could provide a more rapid and comprehensive orchard assessment. UC Davis ag engineers Vasu Udompetaikul, Shrini Upadhyaya, David Slaughter, Bruce Lampinen and Ken Shackel have mounted this suite of sensors to assess water status on a Kawasaki mule which is driven through the orchard.
Resources and links mentioned in this article can be found on the Almond Board website irrigation management page, www.AlmondBoard.com/Farmpress29.