Issue link: https://www.e-digitaleditions.com/i/1349956
ALMOND ORCHARD 2025 GOAL Greer said pressure losses can be due to poor design, leaks or plugs, resulting in vastly different quantities of water applied throughout the orchard. "This variance can have a big effect on plant health and yield, which translates to dollars and cents for the grower," he said. Following a free RCD irrigation evaluation, growers are provided a confidential report summarizing their system's irrigation performance. The report includes a DU rating, a system map of pressure and flow measurements, and specific recommendations for improvements and maintenance. "From our report, we learned that not all our sprinklers were efficient, which was a shock to me," said Chad Johnson, a Capay grower in Glenn County who had two orchards evaluated by the Tehama County RCD Mobile Irrigation Lab. "We had some leak issues and discovered that our gallons-per-minute in the main line were down due to some filters. We also found that we were underirrigating in some spots and irrigating too much in other spots." Grower James Lefor and his family have worked with the Tehama County RCD for more than six years. "Every time we plant a new block, we have Kevin come out and check everything to see if what we believe we're putting out is actually what's going in the ground," Lefor said. "Between all our fields, we usually see him every year. I tell all my neighbors about it because it's a great service and we need to be cognizant of the finite amount of water we have every time we irrigate." Going beyond DU to quantify losses Last year Devol and Greer set out to go beyond the traditional DU test by quantifying losses due to irrigation system leaks commonly seen in the orchard. "When growers run a system, they run it anywhere from 20 to 30 hours," said Greer. "A single 0.2 gallon-per-minute leak doesn't sound like much, but when you look at that amount over a 24- hour period – and 10 to 20 irrigation events throughout the year – you start to see big losses with just a single leak." As an example, Devol sites a filter on a flush valve that was leaking at a rate of 0.61 gallons per minute. He calculated that if left unchecked, the leak would amount to 20,733 gallons of lost water over the course of an irrigation season where 42 inches of water was applied. "In a traditional DU test, you might see a leak, you note it, and then you move on to your next spot in the orchard," Devol said. "Kevin and the Tehama County RCD are trying to give growers some insight into what the true cost of leaks adds up to. They've been great collaborators in this process." Findings from last year's evaluations by the Tehama County RCD Mobile Irrigation Lab revealed that 59% of systems had clogged emitters or sprinklers with no flow, while 33% of systems had leaks in tubing, fitting or sprinkler lines. Also commonly found were clogged screens, which can result in a significant reduction of pounds per square inch (psi) in system pressure. "Last year was the first step in actually putting a hard number on water losses," Devol said. "This year, we want to go a step further and look at the cost of the water that was lost so we have a dollar amount to associate with the volume lost. "Speaking in dollars and sense is an effective way to encourage change." Visit Almonds.com/Irrigation for more information on water efficiency practices. "You can't manage what you don't measure." — Tom Devol Greer measures the amount of water lost from a leaking filter gasket at an orchard in Glenn County. ABC and Tehama County RCD are partnering to better quantify the volume and cost of leaks in orchards. Almond Board of California 6 Schedule Your Distribution Uniformity Test Growers in the Northern Sacramento Valley are encouraged to contact Greer at kevin@tehamacountyrcd.org or call (530) 727-1297 to schedule a free distribution uniformity test. ABC also has a formal partnership with East Stanislaus RCD. Please contact Riley Gillihan, Irrigation Technician/ Agricultural Conservationist, at riley@eaststanrcd.org or (209) 287-3674 for more information. Not located in those areas? RCDs across California offer similar free or low-cost technical assistance programs. Contact your local RCD representative to learn more.