Summer irrigation woes offered a good reminder to do winter maintenance on these critical production systems. University of Georgia Cooperative Extension irrigation specialist Wes Porter encourages producers to make the necessary modifications in irrigation system preparation to avoid potential problems during the growing season.
“If farmers haven’t employed a good maintenance plan, ensured good uniformity in their irrigation systems, and done a good job fixing leaks and stopped-up nozzles, it was noticed during the 2019 season,” Porter says. “We had such a hot and dry mid-May to mid-June when corn was in peak tassel, we saw a lot of streaking. That’s usually attributed to poor uniformity.”
Streaking refers to a section of a field where the crops have been underwatered and the effects are visible in the form of smaller plants, wilted plants exhibiting stress and those with a canopy that is not fully developed.
Irrigation issues that can lead to streaking include clogged nozzles, leaks and inadequate or aging pumps.
“Usually, when we get to the point where we start seeing these maintenance type of issues in a normal year, we have had enough rainfall to mask some of the problems,” Porter says.
According to the UGA Extension Corn Production Guide, corn needs the most water — approximately 0.33 inches per day — during pollination. If malfunctions exist and corn doesn’t receive the right amount of water at the right time, the amount and size of the corn kernels could be impacted.
Porter points out that while you may see water coming out, if you are not certain it is coming out at the correct rate, you may not be applying what is needed by the corn plant. “It will be easy to tell if there was an irrigation system problem on the yield map, as the yield reductions will follow irrigation system patterns.”
Porter recommends farmers thoroughly inspect their irrigation systems and make needed repairs once harvest season is done.
Before next season, conduct thorough maintenance of irrigation systems based on company recommendations. These tips are a good place to start:
■ Make sure to do an electrical system shutoff beforehand or risk electrocution. You’re working with 480 volts, so make sure the power is turned off in your work area. Proceed with electrical safety in mind.
■ Check the power unit, especially the main control panel, for any issues. Make sure all fuses are in working order and that no animals have chewed on wires or built nests in the electrical control box.
■ Check the pumping system to see if pressure and flow are optimized. If pressure has been lost from last year or the pressure spikes, there’s more than likely a leak or possibly a clog. Check the sprinkler systems to make sure they are functional and properly applying irrigation.
■ Perform a uniformity check on the pivot to determine any nonvisual application issues.
■ Check the pivot point as it could contain leaks, loosened bolts, bad fittings and improperly greased joints.
■ Check the drain valves to see if they’re in proper working order. When the system shuts off, the valves should drain water out of the pipe and should prevent leaks at the drain areas when the system is full of water.
■ Make sure that the auto-stop and reverse are working.
■ If chemigation or fertigation are being used, check their respective pumps.
■ Check to see if the drive motors at each tower are in proper working order and that there is nothing nesting on the inside.
■ Check the tires to make sure none have leaks, cracks or are flat.
“The last thing you want to do in the summer is go out in the middle of a corn field to change a tire or a drive motor. It can be hard to get to,” Porter says.
For a more complete checklist, read UGA Extension Bulletin 1452, “Spring Center Pivot and Lateral Irrigation System Preparation.”
Article provided by UGA College of Agricultural & Environmental Sciences.