Close spacing combines low-pressure precision irrigation bubbler heads made for LEPA (Low Energy Precision Application) with conservation tillage practices to improve efficiency of water use with center pivot irrigation. Close spacing typically achieves application efficiencies of 95% or more.

LEPA systems deliver water just 8 to 18 inches above the ground to combat wind drift and prevent evaporation loss. Researchers and growers have found that with LEPA heads used with the right application, at least 20% more water reaches the soil than with conventional spray nozzles.

Unlike traditional LEPA systems where sprinklers are placed 60 to 80 inches apart to irrigate alternating furrows, the close spacing method distributes water over most of the soil surface by placing the sprinklers no more than 40 inches apart.

Conservation tillage practices further minimize evaporation loss and run-off by holding the water on the surface until the soil can absorb it.

Benefits

• Maximize effectiveness of water usage with center pivot irrigation
• Prevent wind-drift losses
• Minimize evaporation loss
• Avoid wetting plant canopy
• Achieve more uniform root zone coverage
• Can increase yield using less water through precision irrigation
• Can help leach salts
• Reduce pumping costs
• Reduce pivot passes
• Less potential for rodent damage to crop and equipment compared with drip systems
• Qualifies for government funding in select areas
• Can be used on high- and low-profile crops

For best results, fields should incorporate:

• Closer drop spacing – 40 inches or less between sprinkler heads
• Sprinkler height 8 to 18 inches above ground with loaded machine
• Conservation tillage to increase surface storage capacity and improve filtration
• Level fields – ideal maximum slope is 1%
• Soil moisture monitoring to reduce deep percolation losses

One thing that irrigators should keep in mind is use of close spacing with sloping terrain. If the field has moderate to severe slopes, this method could enable significant runoff and negate the wind drift and evaporation savings. To ensure your sprinkler package is designed for the best possible outcome, contact your local Valley dealer.

Here’s what growers say 

“We seldom would get more hay on the second cutting, but with the LEPA bubblers, one pivot gave us 40 more bales.”

“Converting from sprinklers to close-spaced LEPA applicators has allowed me to farm 50% more corn (120 acres) with 250–300 gpm.”

Water Savings –

“With the windy conditions in the valley, it was evident that the LEPA bubblers were simply not misting like our other pivots with traditional sprinkler systems. Water typically lost to evaporation and wind drift was saved.”

“The low-to-ground delivery reduces wind drift and evaporative loss and the close spacing uniformly soaks the soil for good root development. I am amazed with what I can do for less.”

Reduced Energy Costs –

“Because close-spaced LEPA bubble systems run at 10 psi, they consume very little energy. We don’t have to run these systems as long as traditional sprinkler systems, so our power bill went down.”

Better Soil Quality –

“The deeper, even water penetration is evident. The soil beneath the close-spaced LEPA systems feels softer to walk on.”

“The water in our area is high in calcium. LEPA bubblers get more water into the soil and help flush the salts deeper. With in-canopy application, the salts don’t rest on the crops, which helps produce more and bigger leaves.”

For more information about close spacing and LEPA sprinklers, contact your Valley_® dealer or visit www.senninger.com.