Kenny Marsh excused himself for a few minutes before driving around the 12,000-acre Triangle T Ranch in Chowchilla, Calif., to be interviewed about the 27 center pivot irrigation systems that have been installed on the diversified farming and livestock operation.
He was busy working with a ranch office staffer in entering information in a database he custom-designed for the 63 active irrigation wells on the farm.
Marsh is assistant manager of Triangle T where his father, Doug, a well known Madera County farmer, has been farm manager for many years.
Marsh grew up working on the farm before going into the Air Force where he became skilled with computers. After the service he augmented his military experience with computer classes from ITT Technical Institute. His resume also includes working several years as water master for the Chowchilla Irrigation District, a job experience he enhanced with irrigation courses at Cal Poly, San Luis Obispo.
At his desk in the ranch office are two large flat screen monitors connected to the ranch’s computer network. A laptop computer sits on the edge of the desk. In his truck are a myriad of communication gadgets. One of the cup holders is occupied with a hand-held GPS unit.
Marsh is part of the new wave of agricultural technology that he says has grown “exponentially” in the past few years. There are three GPS towers on the Triangle T. Virtually all the farm’s tractors are GPS-equipped.
All 63 pumps entered in to the database Marsh designed contain vital pump information like energy use, water output and pump test efficiency information — in addition to GPS coordinates for each pump location. Why? Pumps don’t move. However, as Marsh explains, they need to be located correctly when services go out or there is a problem. The coordinates send people directly to the right pump.
Marsh applies technology to his job with a vivid memory of driving his first tractor, a D-7 Caterpillar dragging a stubble disk. “When people talk about saving 18 percent in labor and fuel costs disking with GPS, I know what they are talking about. I remember steering that tractor in the dust trying to keep a straight line, overlapping 2 or 3 feet to make sure it all gets covered; I understand how you can save a lot of money on fuel and labor with GPS because that is the kind of money GPS can save you” he says.
He also can recall moving sprinkler pipe hand lines. “That is the reason my back is messed up,” he laments.
So when it came time to move up to more efficient, technologically advanced irrigation methods for the farm’s field crops like alfalfa, corn and cereal grains, Marsh’s recommendations were straight forward.
“There were three choices to move from flood and furrow irrigation: hand lines, wheel lines or center pivots. There was only one choice in my mind; center pivots,” he said.
Over the past six years, 27 Lindsay Zimmatic pivots have been installed on roughly 3,800 of the Triangle T’s 12,000 acres. They were first put on new ground that was in pasture for conversion to cropland.
“We have one more to put in, but we have not decided where,” he says.
To Marsh, the pivots were a no-brainer because of the reduced labor costs they represented and the technology they offered, like wireless telemetry. They can all be turned on via phone or computer.
He points to the nine pivots on about 1,400 acres of alfalfa near the farm’s offices as an example of labor savings. One man takes care of irrigating that acreage and more. Under flood, it would take two or three times that many and still not get covered between cuttings.
“Before the pivots, it was taking us 28 to 30 days to get around all that alfalfa, and we still could get only about two-thirds of it irrigated before harvest,” he says. It was actually a 45-day job of opening and closing ditches and letting water slowly creep across checks.
To cover the entire 1,400 acres between 30-day apart cuttings required a bigger water supply … not necessarily more water. “By using the pivots we have been able to stretch the available water supply. Without the pivots, we were looking at putting in at least three new wells at a cost of $250,000 to $300,000 apiece,” he notes.
The water application rates match the soil infiltration rates with Nelson sprinklers suspended 3.5 feet above the ground to minimize wind drift and evaporation. He calls it a “middle of the road” irrigation package. He can quickly change sprinkler packages on each span to match crop conditions.
After a cutting, Marsh runs the pivots at about 42 percent of their maximum speed to match the soil infiltration rate.
It takes about 24 hours to irrigate a 140-acre circle. He comes back a week and a half after the first irrigation and irrigates again, shutting the water off three days before cutting. He green chops the first and last cuttings and bales the remainder of the seven to eight cuttings he gets annually.
“We will put on a normal 4 to 5 acre feet of water that alfalfa requires per year, but with the pivots apply it right. It stays lush and green,” he says. After this year, he will have good yield numbers.
“All you have to do is look at the corners where we do not sprinkle, but flood irrigate. They dry down a lot more between irrigations than what is under the pivots,” he notes.
“I can also turn up the pivot speed to give it a quick drink if it needs it,” he adds. The flexibility is so much greater with mechanical irrigation than with flood irrigation and the opening and closing of ditches that goes along with that, he notes.
One of the big drawbacks with pivots in California in the past has been the yield loss associated with field corners. Marsh estimates he losses about 18 percent of a section by irrigating in circles.
Right now Marsh is flood irrigating the corners, but he says some growers who have had more experience with pivots than he has say what is gained under the pivots in yield and quality offset what is lost in the corners and they do not farm them. Other growers with pivots have installed drip systems in the corners and farmed high value crops like blueberries. Experience will offer more insight into how he farms or does not farm the corners.
Moving to any automated or mechanical irrigation system is not cheap. “We try to keep the cost of new irrigation systems to about $1,000 per acre,” said Marsh.
Triangle T’s water costs average $85 per acre foot. Wells range from 400 feet to 1,000 feet deep, most on the shallower end of that range.
“Right now with the alfalfa market like it is, alfalfa really does not pay, regardless of your water costs. However, we look at center pivots or any other technology on a long term basis,” he said.
“We also went with pivots because they are relatively easy to move around,” he adds.
The technology with the Lindsay systems is very good, says Marsh. “Their service is good. That is important.”
He also injects fertilizer through the systems, which is another labor savings.
He gets a lot of questions from fellow farmers about the pivots and admits many growers are reluctant to try new technology.
“I tell growers it is a very efficient way to irrigate, but you cannot just turn them on and forget them,” he said.
Although pivots and lateral moves do not get stuck as often as they once did due to more advanced sprinkler packages and the use of booms to improve the spread of the water, wheels can bog down. “We pack all of our wheel ruts and sand them. We have had only one problem. The fail-safe system worked and the sprinkler shut down, but the pump did not and we had a mess,” he notes. “However, it has happened only one time.”
While he is pleased with the pivots, he adds that the ranch is looking at the current subsurface irrigation of alfalfa several growers are trying as maybe the next advancement in irrigation. Triangle T is moving into high value crops such as tomatoes and onions like other growers and Marsh says subsurface drip will likely be the irrigation system of choice there.
“Flood and furrow irrigation is so inefficient. With the rising cost of water and labor, we have to move into new irrigation technology,” he remarks.
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