What is in this article?:
- Irrigation cuts costs, worry for North Carolinaâ€™s Todd Lewis
- Knows how they work from the ground up
- Two thirds under irrigation
- Has to conserve inputs
• With today’s high input costs, Todd Lewis says, high yields are a must, but being able to produce good yields and at the same time make the land better for future generations through sound conservation programs, is his long-range vision.
HIGH INPUT COSTS make high yields critical to profitability and sustainability says North Carolina grower Todd Lewis.
Knows how they work from the ground up
In 1985, he built a 17-span, 2,700 foot pivot that is capable of applying 2,250 gallons of water per minute. Not only is it big in size, it also proved to be big in teaching Lewis the importance of knowing how irrigation pivots work from the ground up.
“We learned from that project that irrigation is a 24/7 deal, and that to keep them running efficiently — especially during peak times in crop production — we need to be able to service them ourselves. Saving a little money is a side benefit, but having our own people on the farm to fix things when they break is much more valuable than the money we save.”
When he started installing pivots on his farm, Lewis had one diesel pump and one 12-inch pipeline from the pumping station to the pivot. Another valuable lesson he learned early on is that a larger pipe line is cheap compared to the increased horsepower consumption caused by friction loss trying to push too much water through a smaller diameter pipe.
His 10 systems all run off the same pumping station that was converted to electricity, but he has added multiple 10-inch and 12-inch lines. Reducing water pressure and horsepower, he says, has made the systems more efficient and less costly.
“On the big 17-span pivot we first installed, we used to run 120 psi of water pressure at the pump to get the needed 60 psi at the pivot. With the electric system and the enlarged pipelines, we can run 85 psi at the pump and still get the needed 60 psi at the pivot — that equates to a savings of 50 hp. Another big savings was the addition of a variable frequency drive connected to a pressure transducer to automatically control the speed of the electric pumps.
“I’m confident we can now run all our pivots easier and more efficiently than we used to run that first pivot plus two reels,” Lewis says. He still uses two large reels to irrigate areas of fields not covered by pivots, but says the reels are not nearly as efficient as the electric-powered pivots.