Flooding Dormant Orchards for Groundwater Recharge

Tim Hammerich

News Reporter

One of California’s most precious resources is below our feet: the water stored in underground aquifers. In dry years like the one we are experiencing now, surface water becomes scarce, and we rely on these aquifers to make up some of the difference. Researchers like Helen Dahlke at UC Davis believe that recharging this groundwater is an important part to a more sustainable future. This could include flooding orchards during dormancy.

Dahlke… “We've only been able to do a few studies on perennial crops. We actually did one with the California Almond Board and we only applied about two feet of water in the winter on two almond orchards. And both of them received the water in January, so well within the dormancy period. We did not see any negative effects on yield. We actually did see a positive effect on the hydration status of the trees. So some of the trees in the flood treatments did stay more hydrated during the growing season so they didn't need as much irrigation water. And also seems to have no effect or no negative effect on root growth. So your roots are actually the crucial part because they are the ones responsible for taking up water and nutrients. And we did not see any negative effect on root growth or lifespan of roots.”

Dahlke emphasized that groundwater recharge is just one action that will be required to maintain our water resources.