What measurement is used to determine rate of travel in center pivot chemigation calibration?

• A. The distance traveled by the last tower in 10 minutes
• B. The total number of towers
• C. The height of the sprinkler nozzles
• D. The diameter of the pivot

Answer: (A)

Rate of travel is the speed at which the center-pivot system moves across the field. To determine it, you measure how far the last tower travels in a fixed time period (commonly 10 minutes). This distance divided by the time gives the travel rate (feet per minute). This measurement is essential because the application rate you achieve with chemigation depends on both the nozzle discharge and how fast the pivot is moving over the field; change the speed and you change how long any given area is exposed.

The number of towers, the height of the sprinkler nozzles, or the diameter of the pivot don’t tell you how fast the system is moving.