Inspecting Irrigation Pivots After Harvest

Before you put your irrigation system to bed for the winter, inspect the center pivots for repairs and evaluate their performance.

Steve Melvin is an extension educator at the University of Nebraska. He says the best way to check the pressure is with a pressure gauge. Every center pivot has a means of checking the pressure at the pivot point, but gauges that have been out there for a few years may not be working anymore.

"You would need to install a new pressure gauge on there. Or, you can get a little Schrader valve which is a small little device that makes like a valve stem on a tire and then you can just use a good pressure gauge with an air chuck on it to check the pressure," says Melvin. "Also, put one of those out towards the end of the pivot when the pivot is on the highest point in the field and check the pressure there as well."

For the regulators to work correctly the pressure in the pivot mainline needs to be at least 5psi over the rated pressure of the regulator. If it’s too high, the likely cause is plugged nozzles or restrictions in the pipeline. If it’s too low, there may be leaks, a broken or missing sprinkler, or a problem with the pump output.

Also check for uniform water coverage from the sprinklers.

"Probably the best thing that you can do is in the fall, or in the spring maybe when you’ve got more bare soil out there is you can put the pivot to move as fast as it can when it’s applying water, and just kind of walk along and see how uniform the watering is as the sprinkler comes along and starts getting the soil wet," he says.

He says the soil should be uniformly wet along the entire length of the system.