Is Your Irrigation System Honest With You?

March 16, 2023

Charles W. Davis Jr., County Extension Agent, Certified Crop Advisor

With the push of a button and the turn of a valve, your center pivot irrigation system comes to life. Pressure builds, water exits through the nozzles, and the slow process of making a half inch of artificial rain begins on every acre under your system. Or does it? How do you know you are getting a half inch of water added to your field? Is it being distributed evenly? Is it being applied efficiently? Clemson Extension can answer those questions for you and more.

The Clemson Extension Center Pivot Irrigation Test Program (CPIT) is a testing service implemented by Clemson Extension Water Resources, Agronomic Crops, and Horticulture Teams to provide health checkups for center pivot irrigation systems. The test offers measures of irrigation uniformity and helps growers identify and address pivot issues to help save money, maximize crop yield, and conserve natural resources.

When farmers register for the CPIT test on their irrigation systems, they will be contacted by the Extension Water Resource Team member for their area. A test date will be determined, and the farmer will be asked to start the irrigation system and pumps onsite. Usually, two team members can run the test in about two hours. Team members will place catch cups 10 feet apart under the system, and the farmer is then asked to run the system over the catch cups. Each catch cup is plotted on a map, and the water in each cup is entered into the CPIT program. Once the calculations are complete, the farmer is given information on water distribution uniformity, observed leaks, clogged nozzles, or other performance issues. There will also be calculations of designed application rates compared to actual application rates, and calibration charts will be updated for the system. The cost per acre inch of water can also be calculated from information gathered during the test.

Registration is easy. Go to and follow the prompts to register. The cost for the test is $125 per system. For more information, contact your local Clemson Extension Agronomy or Horticulture Agent or the Clemson Extension Water Resources Agent for your County.

 Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, gender identity, marital or family status, and is an equal opportunity employer.