Managing Irrigation for Optimum Efficiency

Almond growers in California have been relying on irrigation for more than 60 years. The Almond Board of California has supported University of California research on irrigation scheduling and management in a range of both high and low volume irrigation systems to determine the optimal use of irrigation water to enhance yields and quality, extend orchard longevity, suppress diseases and insects, reduce energy and optimize available water use.

Optimizing available water became a focal point during years of reduced water supplies. Funded by the Almond Board of California, University of California irrigation specialists have developed management tools for almond growers to optimize water use under various water availability scenarios.

Currently a variety of irrigation systems can be used by almond growers including drip, micro-sprinklers, sub-surface drip, solid set sprinklers and flood irrigation. The choice of an irrigation system depends on a number of factors including the types of soils, the variety of almonds grown, the disease and pest pressures, frost potential and protection, as well as the cost and availability of water.

To ensure that almond trees are neither over, nor underwatered requires the constant monitoring of a number of variables. The timing, frequency and amount of irrigation will depend on a number of factors including weather conditions, the amount of water stored in the soil from winter rains, the stage of development of the trees and the orchard, the soil type(s), the irrigation system type and efficiency. Comprehensive scheduling should be keyed to three factors: (1) weather conditions driving evapotranspiration (Evapo-transpiration [ET] Scheduling) and use of a water budget approach, (2) soil-based monitoring which can use a variety of techniques and equipment, (3) the water status of the trees usually measured with a pressure chamber and plant-based monitoring. A good overall summary can be found at the UC Drought Management Website.

Refer to Western Farm Press, September 2007, for additional information Late-Season Irrigation Affects Almond Yields, Pests

External Links:

UC Davis Drought Management

Website of Dr. Larry Schwankl, University of California Cooperative Extension Irrigation Specialist

NRCS Web Soil Survey (information about an orchard's water holding capacity)

University of California Micro Irrigation Systems Tuneup 

Adjusting sprinklers to reduce runoff

Free mobile lab service in Sacramento Valley

California State University-Fresno Center for Irrigation Technology Agricultural Pumping Efficiency Program offers subsidized testing through a PG&E program

California Irrigation Management Information System (CIMIS) 

Irrigation Management, Terry Prichard, UCCE Water Management Specialist, San Joaquin County

Kern County Irrigation Management, Blake Sanden, UCCE Kern County

Irrigation and Water Resources, Allan Fulton, UCCE Tehama County

Tree and Vine Notes, March 2009, “Principles of irrigation efficiency in perennial crops” by David Doll, UCCE Merced County 

Measuring Crop Water Status in Orchard Crops

Tentative Guidelines for Interpreting Pressure Chamber Readings