Date Palm Irrigation Research Offers Economic and Environmental Benefits

A drip and flood irrigated date palm embedded in the Coachella Valley. All photos by Ali Montazar.

Historically, date palms are grown along riverbeds or in areas with groundwater because they need an abundance of water to produce a good harvest. Unlike lettuce or table grapes, date palms are deceptive in that they do not wilt immediately if they are under water. Eventually, however, lack of water affects yields and fruit quality.

The default for date growers is to apply an excessive amount of water, but this is neither economical nor environmentally friendly. To help growers, Ali Montazar, UC Cooperative Extension's irrigation and water management consultant for Imperial, Riverside, and San Diego counties, has developed insights that empower area growers to establish irrigation guidelines they can use with confidence.

"Water issues in the California desert are very different from those in the Central Valley," Montazar said. “There is no underground water to recharge, so desert growers only have the Colorado River.”

As of 2019, Montazar has focused on date palm irrigation management in the Coachella Valley, the largest date producer in the United States. Montazar's research identifies the amount of water needed for cultivation and the best method of delivering water based on location, soil type and conditions, and date cultivars.

“Dates require lots of heat and light, which is why they do well in the desert. But they also need a good amount of irrigation,” said Robert Krueger, U.S. Department Horticulturist of Agriculture and co-author of an article on date palm irrigation management.

Much of what we know about date palm production comes from the Middle East, which has a climate similar to the low desert of California. "This information is from many, many years ago," explained Montazar, whose research shows that drip irrigation cannot be the only form of irrigation for date palms.

"Ali is the first to really look into micro-sprinklers and flood irrigation for date palms," Krueger said, adding that another benefit of Montazar's research is that it prepares producers to production during periods of reduced water supply.

Drip irrigated date palms in the Coachella Valley.

Albert Keck, president of Hadley Date Gardens, Inc. and chairman of the California Date Commission, described Montazar's research efforts as "subtle but incredible and profound," adding that his findings not only benefit other farmers, but also to cities that depend on water. of the Colorado River.

Keck, one of California's largest date growers, is well aware of how disruptive, costly, and time-consuming irrigating date palms can be. Montazar has enabled growers like Keck to irrigate less without sacrificing yield or quality.

"Ali could save us a small percentage of the amount of water we use. It might be a 5% or 10% saving. That doesn't sound like a lot, but it's an incremental improvement in efficiency," Keck said. "And if you add up all of these improvements, say, along the southwestern United States, it has a pretty profound impact."

Montazar recommends date growers in his area use a combination of drip irrigation and two to three flood irrigation events to manage salinity levels derived from the Colorado River. “We cannot sustain salinity issues over time if we rely solely on drip irrigation of date palms,” Montazar explained.

Flood irrigation pushes salts below the root zone, where they would otherwise accumulate in the root zone, preventing effective water uptake. It also helps fill soil profiles quickly and more efficiently, as the drip has a lower ability to deliver enough water.

“Growers know what they need to water their crop in a larger frame. But Ali narrowed that window and helped us get more precise with our irrigation,” Keck said. room for improvement, but we're spending less money, wasting less time, and using less water now, and we're still getting the same...