Underground Irrigation Makes Headway In Arizona Farming
About 39 percent of all the fresh water used in the United States goes to irrigating crops, and most Arizona farmers use fresh water to flood their fields. It’s a simple and cheap system but, leads to a lot of wasted water. Some farmers in the Southwest are taking a different approach, but it could be difficult to switch deep-rooted traditions to more efficient irrigation.
Driving into Coolidge through the Sacaton mountains, you’ll see an expanse of green cotton and alfalfa fields, most of which belong to David Wuertz’s family farm.
And one thing you won’t see are irrigation ditches lining the fields.
“We’ve taken those out and installed a drip system," Wuertz said. "That’s why we’ve just gone about a half mile and you haven’t seen a ditch.”
Wuertz drives around part of the 3,000 acres he works on to show how the sub surface drip irrigation works. It's a method he said his father has perfected on field crops over the past 30 years.
“He’s pretty much the founder of subsurface drip.”
It works like this: miles of thin hose are buried about a foot underground, with tiny holes running the length. Those emitters control how much water is put out, and saves about a fourth of the water compared to flooding, but because of their small size, can clog quickly.
That’s where a huge filter comes in.
“This is probably the heart of a subsurface drip system,” Wuertz said.
Ten tubs full of sand sift the water before it’s pumped through the fields, similar to a pool filter.
If you ask Wuertz’s whether it’s complicated—
“If you can run a swimming pool, you can run a drip system,” Wuertz said laughing.
And he has six of these sites around the fields.
Wuertz has seen more and more farmers in Arizona using this techniques as it’s become more accessible.
“[With a] subsurface irrigation system, you can pretty much buy all the parts off the shelf now," he said. "So it’s not a mystery anymore.”
But those filter setups cost about $30,000 each, and the drip tape itself is around $1,500 an acre. So while the Wuertz’s are saving a lot in water and pumping costs, they’ve sunk a lot of investment into the infrastructure.
Arizona's Irrigation Future
Up north in Camp Verde, water rushes through a control gate to irrigate Kevin Hauser’s family farm, which uses the same drip technique but on a much smaller scale and budget.
“We’ve done about 10 acres of drip on sweet corn and pumpkins,” Hauser said.
Arizona’s Nature Conservancy worked with Hauser to install the filter and drip line as a way to boost efficiency and help preserve the Verde River nearby.
The group’s help also comes with about a million in grant dollars to set it up, something Hauser suggests farmers interested in drip could look for to offset the costs.
“They’re going to have to get the original costs paid for, or cost-shared, or something,” he said.
The Hauser’s experiment has been successful on a few acres of vegetable crops, like watermelons, but near Phoenix, most fields grow wheat or cotton, both of which are more difficult to grow on drip.
U.S. Department of Agriculture researcher Kevin Bronson for the first time is studying how cotton grows on subsurface drip in Maricopa, Arizona – tackling the future of farming with less water.
“Now the further gains that are needed to feed the world and growing population are going to be harder to come by, the increases are at a much smaller rate, but we still want to be heading in that direction,” Bronson said.
Coolidge farmer David Wuertz said another reason you won’t see drip on farms near the city is more development.
“A lot of those fields aren’t going to be farmed very long," he said. "So when you put drip in, you kind of know you’re going to be there farming for awhile.”
What remains to be seen is how permanent agriculture business will be around the Valley.
If the drought continues, and the price of getting water on crops keeps rising, Arizona farmers may be forced to abandon flooding and turn to other methods of efficient irrigation like drip.