Most farmers don’t need a yield monitor to tell them their soils are anything but uniform. They know one area of a field may respond differently than another even if they receive the exact same inputs, including water.

Until recently, that didn’t much matter. Growers were locked into uniform rates of seed, fertilizer, herbicides, insecticides and even water across their whole field due to the limitations on being able to alter their application rates.

That’s beginning to change, however, as farmers like Nebraska’s Tim Schmeeckle and Alabama’s Annie and Mike Dee and others find they can take advantage of new technology that allows them to precision irrigate their fields and grow more corn and soybeans, frequently with less water.

Schmeeckle, who plants 2,000 acres of irrigated corn and soybeans near Gothenburg in Nebraska’s Platte River Valley, believes farmers will have little choice but to reduce water usage for irrigation at some point in the not too distant future.

Nebraska farmers helped pioneer irrigation in the U.S. They began pumping water from the Ogallala Aquifer in the middle of the last century because the dry, western climate often didn’t provide enough rainfall to grow corn. Hydrologists say the Ogallala is beginning to show the effects of that pumping.

“It’s not if, but when,” Schmeeckle says of the coming water allocations. “I want to know how to raise the same amount of corn with less water.”

An admitted “early adopter,” Schmeeckle actually purchased the software and equipment that would enable him to variable rate irrigate (VRI) before he knew how he could make the best use of it.

Valley Irrigation started equipping its center pivots with VRI capability several years ago. When it became available, Schmeeckle began adding the VRI technology as part of a long-term plan for increasing the irrigation efficiency on his farm. He now operates 11 center pivots.

Then, Schmeeckle learned about a company founded by fellow Nebraska farmer, Nick Emanuel of North Bend. CropMetrics, which is now partnering with Valley Irrigation, provides packaged precision ag management solutions with heavy emphasis in the center pivot market.

You have to see Schmeeckle’s farm to appreciate the challenges he faces in growing corn and soybeans. Situated on the edge of the Platte River Valley, his soils rise and fall as you move across the landscape. Soil types vary from fine sand soils to heavier sandy loam and sandy clay loam soils, each of which has a different water-holding capacity.

He decided to first try VRI on a field that falls 45 feet in a quarter-mile. The field averages 175 bushels of corn per acre, but the sandy ridge rarely produced more than 75 bushels. The lower portion of the field, meanwhile, often received too much water, resulting in runoff and nitrogen loss, as well as wasted energy.

CropMetrics surveyed the field using RTK elevation data and a Veris Technology implement, which measures the electromagnetic conductivity of his soil. Soil electrical conductivity typically correlates strongly with particle size and soil texture. Soils prone to drought or excessive water-logging will show variations that can be detected by Veris.

The data from the surveyed field were overlaid with soil maps and yield maps. “I had been saving those yield maps for years, and I wondered what I was doing it for?” says Schmeeckle. “CropMetrics pulled all of that information together and gave me a prescription for watering that field.”

Using the prescription, Schmeeckle’s Valley Irrigation center pivot applied 0.6 inch of water as a base rate for the majority of the field. The prescription prompts the pivot to speed up on the heavier soils, dropping the applied rate to 0.45 inch of water. It slows down on the sandy ridges, applying 0.85 inch.

The field harvested an average of 205 bushels of corn per acre or 30 bushels more per acre than before he used the CropMetrics prescription. The sandy areas of the yield produced 100 more bushels per acre than in the previous year.

This year, Schmeeckle used the CropMetrics approach on eight of his center pivots. With the drought that occurred in much of the Corn Belt along with Nebraska, CropMetrics changed its recommendations to account for the increased water needs of his plants in the heat and lack of rainfall in 2012.

The prescriptive approach doesn’t rely solely on soil conditions. Schmeeckle also works with a company called AquaSpy which installs soil probes that measure soil moisture down to the 36-inch depth. The data from the sensors is transmitted to a computer program that helps him control each of his center pivots.

The system allows him to look at his computer program and determine how much moisture is present at the different soil depths in his field. That information provides another avenue for cost-savings.

Schmeeckle and many of his neighbors are on managed rates with the local utility company. When temperatures go up, the company may ask farmers to cut back on electricity usage to reduce the demand on the system. For that, they receive the benefits of a cheaper rate structure.

In drought conditions like those in 2012, growers may have to stay on the system to keep from reducing crop yields. When they do, they are forced to pay normal rates to keep their center pivots running.

“I was monitoring my soil probes, and I could see that I had adequate moisture at the 8-inch to 12-inch depth,” he noted. So I decided to wait on irrigating. Some of my neighbors turned their center pivots on because they felt it was time to water. But they had to pay higher electricity rates.”

Based on last year’s records, Schmeeckle believes he made an average of seven less circles (revolutions) with the center pivots than his neighbor. At a cost of between $800 and $1,000 per circle, those savings add up.

“In a dry year, I typically will run my center pivots about 800 hours,” he said. “I think I ran them from 250 to 400 hours at most last year. Before, it was a guessing game as to when you needed to irrigate. With this system, you know.”

The 10,000-acre Dee River Ranch in Alabama employs precision irrigation technology on a slightly different scale, but it’s just as important to the future of the operation, according to the brother-sister combination of Annie Dee and Mike Dee, who run it.

“This project will help us reduce risks and make our farming operation more efficient and sustainable,” says Annie Dee of the irrigation effort on the farm located along the Mississippi-Alabama state line near Aliceville. “What’s important to us is sustainability, conserving land and water resources.”

Dee River Ranch is a unique operation. The family goes back to a great-grandfather who farmed in Iowa. They later had an operation in Florida, and they’re now into the fourth and fifth generations farming in Alabama. Besides Annie and Mike, 10 other family members are involved in its ownership.

The precision irrigation project includes a 120-acre reservoir to collect winter/spring rains, a computer-controlled 12,500-gallons-per-minute pumping station that can deliver irrigation water tailored to crop, weather, and soil conditions for up to 15 center pivots, to a super-fast electronic “cloud” that allows people and devices to communicate with each other over a 20 square mile area (or anywhere in the world with Internet access).

With all that, the state of the art system is designed for maximum automation, using the minimum amount of water to get maximum results, with as little energy consumption as possible.

“Our goal is to go beyond sustainability — each year, we’re putting money into improvements, technology, and cropping programs that use minimal resources and put as much back into the land as possible for future generations,” says Mike Dee. “Here in the rain belt, we have abundant water, but unfortunately it too often comes at the wrong time.

“Rather than letting winter and spring rains escape, we want to capture and use that water for crop production. Reservoirs such as the one we have here are another way to capitalize on opportunities by catching and using rainfall that would otherwise just run downstream.

“A lot of smart people have been a part of designing this system, and we believe the long term benefits of this kind of technology can be enormous for U.S. agriculture.”

The installation is “a showcase for the most sophisticated irrigation technologies available today,” said Randy Wood, vice president of sales and marketing for Zimmatic.

“It’s a completely integrated irrigation system, utilizing the knowledge and expertise of all the Lindsay divisions, for a system that will meet Dee River Ranch’s current and projected future needs.

“In addition to providing optimum application rates and high efficiency, these engineered sprinkler systems have chemigation and fertigation capability to extend capital investment and reduce cost per acre. Programmable controls increase efficiency and improve yields by allowing the right amount of irrigation at precisely the right time of the crop’s growth cycle.”

The Dee River system includes five new Zimmatic center pivots, for a total of seven on the ranch, in lengths from 988 feet to 2,023 feet, covering about 1,500 acres of corn, soybeans, and cotton. It utilizes GPS satellite positioning for precise pivot position and end gun control.

All systems have Growsmart FieldBoss control panels and FieldNet Wireless Irrigation Management technology to control all pumps and pivots through an ezWireless broadband Internet network.

John Atkinson, agricultural business manager for Watertronics, a Lindsay company, said the pumping stations were custom engineered and pre-tested, based on the ranch’s specific needs, field conditions, and irrigation network design.

‘The main pumping station has a 12,500-gallons-per-minute capacity, using five 150-hp vertical turbine motors; it can deliver water to 15 pivots. Water is pumped from the 120-acre reservoir, which can store 1,700 acre feet of water, through below-ground pipes ranging in diameter up to 30 inches.

“The transfer pump station has a 7,500-gallons-per-minute capacity, using three 100-hp vertical turbine motors to deliver water from a nearby creek to the reservoir. Water is pumped over 3,000 feet, up a grade of 50 feet.

“Watertronics variable frequency drive technology is used in both pumping stations, and both are controlled and monitored by FieldNet Wireless Irrigation Management. System status is transmitted every minute over the wireless network and can be monitored and controlled by computer or smart phone anywhere with Internet access.”

The system will provide precision variable rate irrigation for all pivots, Atkinson says. Each sprinkler can be programmed to turn on/off or pulse at a specific rate, depending on crop, terrain, or obstacles.

“You can select the pivots you want to operate and the system will determine all the variables to provide just enough water, with just the right amount of pressure, to get the job done. It has built-in redundancy and built-in diagnostics to provide alerts to potential problems.

“It constantly monitors and keeps a record of system performance and power consumption.

“The variable frequency drives reduce energy consumption and cost by automatically adjusting to the system’s pressure and flow requirements, always operating at the optimum level, providing surge-free pressure regulation that can cut energy costs as much as 25 percent.”

Need something that is more attuned to furrow-watering systems, but still precision-farming oriented?

Mississippi State University scientists are evaluating software that could help increase irrigation efficiency for producers who use plastic tubing or gated pipe.

The software is called PHAUCET or Pipe Hole and Universal Crown Evaluation Tool, and MSU specialists say it has the potential to reduce the amount of irrigation water being pumped from the Mississippi Delta’s alluvial aquifer and other water sources.

“PHAUCET has the potential to reduce water pumped from the Delta’s underground water supply.

This supply has declined over the years because of traditional irrigation approaches and increased irrigation acreage,” says Jason Krutz, MSU Extension irrigation specialist.

The software was developed by engineers with the U.S. Department of Agriculture’s National Resources Conservation Service in Missouri, but it could have applications in a number of southern crops.

The program uses engineering equations to calculate pipe pressure and flow rates for each watered furrow. It applies system flow rate, pipe diameter, watered furrow spacing, row lengths and elevations down the length of the pipe.

The user can select a hole size design in the plastic pipe for each watered furrow to deliver water uniformly without bursting the pipe.

“The program can compute proper hole size designs for fields that vary in layout from fairly square to rectangular to less conventional layouts,” Lyle Pringle, a systems engineer with MSU’s Delta Research and Extension Center at Stone-ville, Miss.

The PHAUCET irrigation design should allow water to reach the end of long or short rows more uniformly. Thus the producer will not waste water through runoff while waiting for other rows to finish watering, saving time and money.

The savings gained with PHAUCET could be lost if the irrigation is allowed to run longer than needed, so proper irrigation timing is necessary.

Timers that shut off the well automatically can help with irrigation management, said Joe Massey, an MSU plant and soil sciences professor who is working with Krutz, Pringle and MSU Extension and research professor Tom Eubank to field test the software.

“For example, if a producer expects that an irrigation set will finish early in the morning, say at 2 a.m., but he or she is unable to shut off the well at that time, excess water could run off the field, reducing the water and energy savings normally associated with PHAUCET,” Massey said.

“Installation of a 24-hour spring-wound timer on both electric and non-electric wells would increase the efficiency of PHAUCET by letting the producer set the timer to shut the well off at a specific time.”

Producers can check the field and assess how well the crop was watered at a time more convenient to their schedules. In most cases, timers should pay for themselves in about two seasons, he said.

“PHAUCET could increase water use efficiency while at the same time reduce watering times and thus reduce producer costs in irrigation,” Eubank said, whose work focuses on soybeans.

Many Mississippi soybean producers irrigate their crops five or six times a season by applying 2 to 4 inches of water an acre per irrigation.

“We have compared PHAUCET with standard irrigation practices on several producer fields, and analyzed the number of irrigations during the season, the amount of water, the duration of each irrigation event and soybean yields between both systems,” Eubank said.

Preliminary results over a three-year period have shown about a 20 percent savings in both pumping times and water use with the PHAUCET system over the conventional system, he said.

“We hope that these numbers will continue to hold true. If they do, and PHAUCET is widely adopted, farmers could reduce or reverse the declining underground water table,” Krutz said.

The Mississippi Soybean Promotion Board is funding this research. Producers can download the PHAUCET program at no charge from the Yazoo-Mississippi Water Management District’s website at www.ymd.org/phaucet.htm.