On a warm February afternoon, Kirk Pumphrey walks down his rows of almond trees at Westwind Farms in Yolo County. He notices the buds on the branches have already sprouted pink. It worries him. The earlier the trees bloom, the more likely winter frost will damage the nuts. Early blooms are occurring more often as higher temperatures from climate change stimulate plant growth.

California’s warming climate also means thirstier trees and an increasing reliance on groundwater, especially during drought. UC researchers found that farms pumped 27% more water from aquifers last year compared with 2019.

But Pumphrey has tapped 5% less water from these sponge-like underground stores of water in the past year, before the state ended its driest three-year period on record. He’s managed to save water in part by using a type of precision metering called pulse irrigation. Sophisticated sensors predict when the trees need little pulses of water, just enough to replace the water they lost to the atmosphere the previous day.

“It’s the difference between drinking from a firehose or having a glass of water,” Pumphrey said.

Read more at University of California, Davis

Image: Kirk Pumphrey of Westwind Farms stands in his almond orchards in Yolo County, California. He’s using a precision metering and almond mulch to conserve groundwater. (Credit: Karin Higgins/UC Davis)