Almond Grower Slashes Water Usage
The drought in California has reached dire proportions, landing agriculture directly in the regulatory line of fire for those seeking to re-evaluate water usage across the state. Growers are facing continued pressure to do more with less, and as a result, many have risen to the challenge by dramatically reducing their water usage along with other valuable inputs.
One operation that stands out in the water conservation category is Dan and Tom Rogers Farming in Madera County, CA, which received the 2014 Farm Water Steward Award for its conservation efforts.
Tom Rogers grows 175 acres of almonds alongside his brother, Dan. The operation has been in business for almost 100 years and recently made the switch from surface water to groundwater, like many others in the state.
“This year and last year are the only two years in our irrigation district’s history that they have not delivered surface water. We’ve had to run our deep wells to irrigate the last two years. That’s been the only source of water and it’s really putting a strain on the underground water supply,” Tom Rogers says.
Transition To Drip
To cope with the change, Rogers made some major adjustments to his irrigation system, transitioning from micro sprinklers to double line drip, which provided the operation with a 25% reduction in water usage over the previous year.
The new system, which is made by an irrigation software company named Wiseconn, utilizes fully automated valves that Rogers controls through software on his computer, and is programmed to release the water in one-hour pulses, moving it laterally through the soil.
“The valve automation is what makes a huge difference. Any time you run water for a long time in one place, you’re going to pool water on the surface and that water can evaporate,” says Rogers. “What we’re trying to do is match the infiltration rate of the ground. Some ground will allow water to flow in freely, and with other ground it just takes longer to get water in.”
The program is relatively simple, Rogers says. Users can pick any irrigation duration that is appropriate for the crop. This system also gives users the ability to adjust the valve timing to match the crop needs.
To make even better use of his available water, Rogers regularly monitors weather conditions, tracking his trees’ evapotranspiration (ET) rates by using weather stations situated throughout the orchard. That ET data, combined with ET rates from University of California Cooperative Extension’s in Madera County branch, allow Rogers to more accurately assess how his trees use available water.
Rogers explains another recent change to his irrigation system due to a key observation he made regarding tree root systems.
“One thing we learned this year is that almonds do a majority of their work in the top 18 inches of the soil. So I’ve moved most of my soil meters up, and I now read my moisture at 6, 10, 14, 18, and 22 inches because that’s where the activity is,” he says.
As soon as he sees the tree roots pulling farther downward for moisture, he knows it’s time to irrigate. However he’s still sure to monitor the moisture at 36 inches to make sure he’s not overwatering.
Despite the major gains Rogers has made with the new valve system and improved technology, he believes there’s still room for improvement.
“With almonds, we’re using 30% less water today than we were 20 years ago. That’s a pretty amazing step forward. Can we do more? I absolutely think we can.” ●