Issue link: https://www.e-digitaleditions.com/i/1170186
A L M O N D O R C H A R D 2 0 2 5 G O A L S WATER USE 3 Aquifer Recharge, a strategy that is being coordinated by both the California Department of Water Resources and Sustainable Conservation. 2 Growers leading the charge to recharge One grower already working with Sustainable Conservation is Mark McKean, who grows diversified crops on about 5,000 acres in central and western Fresno County, including 675 acres of almonds near the town of Riverdale. "We were trying to read the tea leaves and saw this coming in about 2010 or 2011," McKean said. "That's when I started doing some experimentation with recharge." One early lesson McKean learned was that his existing orchards were not planned and designed for intentional recharge. So, as he was developing new orchards, he began to adapt, building higher berms to keep tree trunks out of floodwater and making sure new orchards had both drip systems and flood valves to serve both irrigation and recharge needs. However, as verified by ABC-supported research by Dr. Helen Dahlke of UC Davis, not all sites are ideal for recharge. 3 It's helpful when soils are well-drained and water can infiltrate quickly, and timing is critical as growers should look to recharge when trees are dormant, if possible. With that in mind, McKean said he isn't designing his orchards that are on heavy, alkaline soils for recharge. "You need to have the right soils for recharge, and growers know their soils best. Recharge is not going to work for every grower, every orchard, but it will work in some places," McKean said. "The key for growers," he said, "is beginning to learn what will and won't work in order to be ready as local GSAs begin to implement recharge crediting schemes, which involve banking, trading and other incentives for recharge." Research determining impacts on nutrients, optimal sites Knowing when and where to try groundwater recharge, and how to do it without damaging crops, are key decision points for growers. For this reason, ABC invested in Dahlke's research and other projects to determine how to manage nutrients in combination with recharge. Roseman noted that ABC also recently funded research led by Stanford University physicist Rosemary Knight, whose project is helping to develop new and less expensive ways to evaluate sites for their recharge potential. This type of work could help individual farmers and GSAs evaluate where to prioritize their efforts. "Right now, evaluating sites for their recharge potential requires field-level research with test wells and similar investigation," Roseman said. "This study could help determine whether we can get that information less expensively with remote sensing." Meanwhile, ABC has invested in groundwater recharge potential maps as part of a larger mapping project to improve the precision of information about the almond community. The maps were developed in partnership with Land IQ, a Sacramento-based agricultural and environmental scientific research and consulting firm. Land IQ's 2014 almond mapping data indicates that nearly 675,000 acres of almond orchards grow on soil that is moderately good or better for groundwater recharge. This includes 4,119 acres of almonds that are categorized as "very good" in their groundwater recharge potential; 271,509 acres categorized as "good" and 396,790 acres categorized as "moderately good." Growers can access the maps by visiting Almonds.com/Maps. Message remains: Get to know SGMA McKean, who also serves as chairman of the North Fork Kings GSA, said he's seeing increased interest among growers in SGMA, local plans to achieve groundwater sustainability and groundwater recharge. "There are a lot of people asking a lot of questions and coming to our GSA meetings, and a lot more growers are aware that there is going to be change," McKean said. "They are trying to figure out how to make it work for themselves." McKean's advice to growers: "Pay attention to the details." McKean added that growers should keep SGMA and potential recharge in mind as they consider how to construct their orchards. "Overall," he said, "growers should remain informed." "It truly benefits growers to go to these GSA meetings, or go to GSA websites to get information on what works for them in their circumstances," McKean said. "Everybody needs to rethink their approach." Growers can learn more about SGMA at sgma.water.ca.gov/portal. The California Farm Bureau Federation has also prepared a helpful brochure, which can be accessed at www.bit.ly/2Ktswr6. 2 https://water.ca.gov/Programs/All-Programs/Flood-MAR 3 https://www.youtube.com/watch?v=311GGoCWXMY This flooded almond orchard in Fresno County was part of a spring 2017 on-farm groundwater recharge effort that involved applying available floodwater from the Kings River to an active orchard to help refill an over-drafted aquifer. (Photo by Paolo Vescia) Continued from page 2