Irrigation Meets Innovation
January 21, 2012
Variable rate technology, as a component of precision farming, is moving into many facets of agriculture, including fertilizer, seeding, fungicide and herbicide applications and its now available for irrigation systems, writes Sarah Mikesell, TheCropSite senior editor.
Kevin Abts, VP of Sales and Marketing with CropMetrics in North Bend, Neb., explains that his company specializes in optimal rate irrigation prescription generation for farmers who want to use field data to more efficiently apply their water through a center pivot. Working in partnership with Valley Irrigation out of Valley, Neb., they can create variable irrigation prescriptions for virtually any center pivot.
"We have new technology that allows us to take electromagnetic (EM) or electrical conductivity (EC) data and process it to identify field variability," Abts said. "The resulting data layer can then be uploaded into our specialized Virtual Agronomist software. The field can then be divided into smaller, more precise management areas either in the form of pie-shaped sectors or even smaller zones along the irrigation span."
The prescriptions are compatible with either Valley VRI Speed Control or VRI Zone Control equipment that variably controls water application depth on virtually any center pivot.
For example with VRI Speed Control, the pivot will speed up and apply a little less water to heavier soils. Likewise, the pivot may slow down and apply a little more water to the lighter soils. Abts said this can be done effectively every two degrees for up to 180 sectors with the Valley Pro2 or Select2 control panel or remotely through the TrackerLT. The TrackerLT provides a remote monitoring and control option for most any brand center pivot.
If growers want a more advanced control product due to more field variability or if there are non-cropping areas they don't want to water, Valley offers VRI Zone Control. It uses the Pro2 control panel, special VRI Zone Control units on the span and sprinkler control valves to manage individual or banks of sprinklers along the length of the span. It will allow anywhere from one to 5,400 individual control zones for true precision irrigation.
"Over the last decade, growers have made substantial investment in precision ag technology, including autosteer equipment, yield monitoring and variable rate fertilizer," Abts said. "Many growers are using variable rate seeding as well, indicating the market understands the value of precision agriculture. Through the integration of new precision ag technology with Valley controls, CropMetrics and Valley now offer the most advanced irrigation management solution in the industry."
Jake LaRue, product manager with Valley Irrigation, says one of their goals since the center pivot was developed was to uniformly apply water across the whole field which they now realize may not be the best solution if the grower's field is not completely uniform with homogeneous soil types and level topography.
"The reality is, there isn't uniformity in many fields - there are variations with a lot of different possible combinations," LaRue said. "For a farmer to be more efficient and profitable, he needs to apply different amounts of water to different soil types in different areas of the field."
LaRue said the CropMetrics' technology is cutting-edge.
"The ability to really do this - put a specific amount of water where you actually want it - it's finally here," he said. "It's not for everybody, but it's now an option that allows a grower with field variations to maximize their water resources."
Last year with two growers they monitored closely, Valley estimates there was about a 12 to 13 per cent reduction in water use and expects to improve on that next year as they build on the baselines they've established.
"Each season is different. Prescriptions that we used last year for customers will be different-because we're going in with different soil moisture, different environmental conditions, different crop situations," LaRue said.
More importantly, he believes, from an environmental aspect, growers are not overwatering areas that could potentially cause leaching or moving fertilizer or other crop inputs below the root zone or into ground water. It's also economically smart for the farmer to maximize the efficiency of any inputs that they're applying.
"We believe that this technology is revolutionary. Some farmers recognize the variability in their fields already, and I think, over time, more and more are going to realize that water is precious, inputs are precious, and ask 'why am I treating the whole field the same way?'"
JJ Long, a 3,000 acre corn, soybean and wheat grower from Grant, Neb., had that exact thought. He knew he had significant soil variability on his farm and was looking for a solution.
"I've been aware for years that in many of my fields there are areas that weren't getting enough water, but you never want to irrigate the porous 20 acres to the full extent because in order to do that, you had to really overwater the rest of the field," Long said. "And the only way to change that was to be out in the fields manually changing the speed yourself, and that's just not practical."
He also wanted to get into variable rate fertilizer and seeding, but it didn't make sense to dive in without really understanding where his yield loss stemmed from.
"You might have an area in the field that's not yielding as much, but if you go right into variable rate, you start cutting inputs and seeding rate," he said. "My thought was, if water was the only yield limiting factor that was keeping those areas from producing, let's fix the water first. If we can get the whole field to yield relatively the same by watering the different areas properly, variable rate fertilizer and seeding will be a lot easier to decipher."
He said in the past, when they weren't sure if they should water, they usually erred on the side of caution and put more water on it. However, he knows he's dealing with a limited resource in water and doesn't want to over-water.
"We were always trying to make an educated guess, and it might have been a good one and it might not have been, but it was still a guess," Long said.
"CropMetrics has the most scientific and common sense approach to water management. There's real data that backs up the reasons for the things they do and that's attractive to me. I think I know what I'm doing, but there's no emotion and no debate with their prescriptions. It's data-generated, and that's pretty much the way you've got to look at it," he said.
Long says the ROI is definitely there. He said in one of his fields there had been a 60 to 65 bushel yield variation from the bottom of the hills to the top of the hills, and this year he narrowed that range to a 15-bushel difference - all because it was getting watered properly.
Would he recommend variable rate irrigation speed control to other growers?
"I definitely think so. If you've got pivots that are highly variable-as in rapidly changing soil types in the field-then it looks like a no-brainer to me," Long said. "I really think it will pay in pivots with not as much soil variability too over time."
Long encourages growers to reevaluate their current irrigation programs.
"Every farmer out there thinks that they're doing it right and most of us do a pretty good job." Long said. "But we've all got biases. We all do things that if we sit back and look at it from the outside, we'd see we're doing things that don't make sense because it's the way we've always done it. You have to take that out of the equation. You've got to work with facts and science, and leave emotion behind."
"Water is a resource that we're blessed with, but it's our responsibility to get the most out of the amount we're using. So there are a lot of good reasons to do it: yield, profitability, and intelligent water management."
- Source: Sarah Mikesell, The CropSite News Desk
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