Thursday, March 17, 2011

Dry Wheel Track Options | by Jerry Gerdes

wheel tracks
Wheel tracks
Part-circle sprinkler
Options are available in sprinkler package designs that can help reduce the depth of center pivot wheel tracks. The wheel track depth is a function of the number of passes made across the field and the soil type. As the number of passes increase, the wheel tracks can get deeper, especially in heavy soils. Deep wheel tracks can lead to a drive unit getting stuck, yield losses due to downtime and costly repairs of the wheel track.

One option is to use part-circle sprinklers. With a 180 degree water pattern, the part-circle sprinkler is used in locations nearest the drive unit and positioned to spray the water away from the wheel track, reducing the moisture level in the soil of the wheel track area. Unbalanced forces from the 180 degree pattern require that a rigid drop material, such as galvanized drop pipes, be used to hold the part-circle sprinkler firmly in position. The number of part-circle sprinklers used around each drive unit is dependent on the sprinkler model (full-circle) water pattern diameter. The water pattern from the full-circle sprinkler should not reach the wheel track.

Part-circle sprinkler models are available in both fixed and rotating type sprinklers. It is recommended to use like sprinkler models for both part- and full-circle positions. For example, if a sprinkler package design is rotating sprinklers, the part-circle sprinkler should also be a rotating sprinkler model. Rotating sprinkler models available in part-circle are the Nelson® Rotator and Spinner. Fixed spray models are the Senninger® LDN® (Low Drift Nozzle) and Valley LEN (Low-Energy Nozzle) sprinkler.

A second option is boombacks. A boomback will move the sprinkler up to 15 feet (perpendicular) from the span pipeline, placing the sprinkler beyond the rear tire of the drive unit. The part-circle water pattern will be positioned opposite the direction of travel of the center pivot. Both drive unit tires are more likely to travel on dry soil in this type of installation. For part-circle center pivots or linears, double boombacks are available to place a part-circle sprinkler on each side of the span pipeline. Solenoid controlled sprinkler valves are available to run the part-circle sprinklers opposite the direction of travel when the machine changes direction, turning off the sprinklers in front of the machine.

Discussion Box Challenge

For those of you growing rice with a center pivot or linear this year, or have grown rice with a pivot/linear in the past, what have you done to combat wheel track issues?

Contact Us

Interested in growing rice with a center pivot or linear? Contact us directly!


  1. I saw something similar at an ag show recently. Curious though, does this system work on hilly land where the water washes out the wheel tracks causing the circle towers to get stuck?

  2. I would not expect this system alone to solve the washout (runoff) problem you described. We suggest that center pivot users review the application depth the center pivot is applying. A lighter application depth per pass would help reduce runoff. For example, if you are currently applying 1” or more of water per pass, speeding up the machine to apply 0.5” to 0.75” could reduce runoff.

    The pivot's spray model can also affect runoff. Choosing a rotating spray, which provides a larger water pattern diameter compared to a fixed spray, will minimize runoff in hills and heavy soils.

    Another option to reduce runoff is to use boom backs in all sprinkler locations (full circle sprays) throughout the span, alternating the sprinkler location from one side of the pipe to another. This will further increase the water pattern diameter reducing runoff.