The wheel track of a center pivot or linear machine is of great concern to irrigators. Farmers want to minimize the size of the track so that there is less effect on the soil and the crop.

Conventional installations use a 180-degree sprinkler to keep water away, creating a dry wheel track. The problem is that the flow of a part circle sprinkler is two times that of a full circle sprinkler. The increased application rate actually has the danger of exceeding the soil infiltration rate and producing run-off. This excess water impacts the wheel tracks.

This problem is usually addressed by the reducing the flow rate of these 180-degree sprinklers to as low as 25% of the required flow rate. This lowers the application rate to better match the infiltration rate and minimize the run-off problems. However, reducing the flow rate has a negative effect on the crop yield in the area of the wheel track. Considering a center pivot that has 31,000 feet of wheel track, if you lose 8.5 feet on each side of the track due to lack of water that would mean you would loose 10% of the total area irrigated by the pivot. This would have a serious impact on the financial return of the overall crop.

The use of booms at the towers provides a larger area of instantaneous covers which lowers the application intensity. Applying the same flow over a larger area allows the soil to absorb it at a slower rate. This prevents soil sealing and run-off. With booms, flows can remain the same and allow the crop to receive the water it needs. There is no negative impact on the crop near the wheel tracks. Maximizing crop yield is what every farmer wants.

Booms at the towers spread out the flow over a larger area to help minimize run-off.

The wheel track using booms (left) is tight with the crop on either side showing no negative impact from reduced water. You can see the impact on the crop near the wheel track (right) from reduced water flow from part circle sprinklers.

(Thank you to Francois Davel for content and photography)