Grower borrows an irrigation idea from Greece
Russ Lester calls his innovative elevated irrigation an “upside-down sprinkler system.” The Solano County organic farmer has threaded plastic hoses through the branches of 215 acres of walnut trees, and found enough benefits that he wants to put hose up in the air throughout his whole farm.
“We’ve been evaluating this for six or seven years now,” Lester says. “We farm organically, and try to look at the whole picture, including energy. This idea just seems to be a solution for a number of problems.”
His flood irrigation system was loading water up on one end of the field to the extent that trees on the other end were stunted, and buried irrigation pipe presented other problems, Lester says.
He originally was thinking about how grape growers used trellises to support irrigation hoses, and then he visited Greece. He noticed that farmers there, faced with extremely rocky, rugged terrain, strung water hoses through their olive trees. Lester figured if they could do it, so could he.
• Elevated sprinklers cost less to install than buried pipe.
• Less energy use and lower upkeep are the benefit of hanging sprinklers.
• Elevated sprinklers make it easier to farm organically.
Lester uses both M\,-inch and C\v-inch hose, hanging sprinklers on it like the overhead type used in greenhouses. Among the buried hose problems prevented:
• Weeds by sprinklers. With organic farming, vegetation control around each micro-sprinkler was labor-intensive.
• Mineral buildup in emitters. Again, in organic farming the acids commonly used to clean emitters couldn’t be used. Hanging sprinklers allow all water to drain into the air, leaving no water to freeze.
• Critter damage. Rodents chewed through underground pipes and hoses; jackrabbits chewed sprinklers aboveground.
• There’s no need to locate underground problems, including water losses, whether from leaks, roots pinching pipes — or other water-loss problems.
• It’s better for the trees, since there’s no digging around tree roots of established trees.
Lester was concerned about pruning and shaking the trees with hoses in them, but that hasn’t been a problem. He was also concerned the hoses would sag too much, but found they were fairly stable. He says the workers can cross-mow, another concern, as long as they keep their heads down.
Lester entered into an Environmental Quality Incentives Program contract with the Natural Resources Conservation Service to convert flood irrigation systems on 26 acres of walnuts in Solano County to his new system.
Lester is working with the resource conservation district and NRCS to test the efficiency of some of his systems. While most sprinkler systems operate at 20 to 30 pounds per square inch, he believes he can operate at 15 to 20 PSI.
Brown is the public affairs director for the Natural Resources Conservation Service in California.
This article published in the February, 2010 edition of CALIFORNIA FARMER.