Irrigation Method Saves Power, Water, Moneyby John O'Connell
Capital Press, January 12, 2012
Demonstrations in Northwest will begin this summer
IDAHO FALLS -- Bonneville Power Administration is organizing a series of demonstrations to prove a low-water, low-pressure irrigation method popular in the arid Southwest could save farmers money in the Pacific Northwest.
Low Energy Precision Application utilizes hoses fitted with nozzles and pressure regulators that connect to pivots and release water at ground level, ensuring even and efficient distribution.
Bonneville Power likes that LEPA requires just 6-10 pounds per square inch of pressure, reducing power costs by about a third. Demonstrations will start this summer throughout Idaho, Washington, Oregon and Nevada. The only farm selected so far grows alfalfa in northern Nevada.
Bonneville Power engineer Dick Stroh said LEPA should help farmers in the demonstration curb water loss by 15 percent and reduce flow rates in their pivots by up to 100 gallons per minute without sacrificing yields. Water tends to collect on foliage and evaporate with traditional irrigation methods.
Other LEPA benefits include reduced prevalence of crop diseases that thrive in moisture, improved chemigation distribution and better growing conditions for crops because they don't lose heat to moistened foliage.
Bonneville Power is contracting with Washington State University to run the demonstrations in Oregon and Washington. University of Idaho was subcontracted to handle Idaho.
Troy Peters, a WSU extension irrigation engineer, believes LEPA could work in at least 30 percent of the Pacific Northwest's fields. Flat topography and sandy soils are ideal for LEPA, which can otherwise cause runoff problems. He also recommends growers use a dammer diker, a machine that digs furrows with dams every 10 to 20 feet.
"We want to figure out the parameters under which it would work and under which it won't," Peters said. "We think it works and would be good for growers in the Pacific Northwest, but it just isn't practiced here."
Thus far, Stroh said cheap power and an adequate water supply have kept LEPA from catching on in the Pacific Northwest. As prices of power, water and other inputs continue to rise, Stroh anticipates LEPA will become increasingly attractive -- especially in Idaho, where water calls can occur in drought years.
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