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Making the most of every dollar spent on a field is your goal as a grower. To maximize efficiency as equipment moves across a field, variable-rate technologies (VRT) have the potential to help you achieve that goal by identifying and managing variability.

“Over the past three to five years, we have seen quite a transition to VRT for fertilizer and seed,” says Brian Sieren, who provides market advice and risk-management support for Market 1, Inc. “I think the biggest concern with VRT is the quality of information that is going into the prescription.”

While VRT has the potential to avoid input waste and to increase yields, Sieren feels you need to be very thorough on the information you put into the equation.

“It's the junk in/junk out rule,” he says. “If you do a good job of inputting the proper data, this will overcome a lot of hurdles.”

Taking that first step

How do you move toward a VRT-based system? Collect data. One year of data is good; two and three years are better. The more yield history you have for a particular field, the more likely you are to find the consistent patterns in that field.

“This data lets you pick the low-hanging fruit (fields with lots of variability) for making decisions that are more likely to pay off in saved inputs, like seed and fertilizer, or in improved yields,” says Matt Wiebers, agronomy research specialist with Mosaic Company.

He recommends a systems approach, which combines three elements: the farmer's knowledge of the field, VRT equipment and mapping software, and a local data expert, such as an agronomist or crop consultant.

“A typical example is combining GPS soil tests and yield data that can show potential problem areas in a field,” he says. “A good VRT system will overlay input and yield data without a major amount of data entry effort. It will collect and map the data for you so you can spend your time deciding how to address issues in your field.”

One of the biggest benefits about VRT is that it collects the data as you use it. “You can then look at increases in yield and savings on inputs,” says Wiebers. “Sometimes you can pay for your investment in the first year.”

On the following pages, three farmers share how those data-based decisions are helping them achieve their goal of precisely placing inputs to get the most out of their soils.


Even though Bernerd Hatten pulled his Delaware, Ohio, farm name from a fictional story, what Hardscrabble Farms is doing today with variable-rate technology is completely nonfiction.

“To my great-grandfather, hardscrabble,! meant struggling from meager soils to make a living,” says Hatten's great-grandson Darin Skinner.

As the Skinners celebrated the farm's 100th anniversary this past summer, those meager soils have become a proving ground for variable-rate fertilization.

“My very first experience with variable rate was in 1999 when I saw Tim Norris of Ag Info Tech spreading fertilizer in a field,” recalls Skinner. “When I saw lime coming out of the back of the spreader at multiple rates, I wanted to learn more. So I jumped in the cab with him and started asking questions.”

The answers to those questions led Hardscrabble Farms – which includes Darin, his parents, Gary and Carolyn, and his brother, Brian – to begin variable-rating lime and eventually P and K.

“For us, variable-rating lime is an absolute no-brainer,” he says. “We've got that figured out, and we've seen a big savings.”

But he notes with the P and K, there's a little bit more variability.

“When we look at the maps, we just don't see the variability with lime as we do with the other two products,” he says. “We definitely see more evening of the field. It's not perfect, but I don't think it will ever be perfect. I think it's partially from crop removal. There's always going to be some variability, which is good, because we have the capability to get the soil fertility level where we need it to be.”

To determine rates, the Skinners consult with Ag Info Tech. The company does grid sampling and then provides prescriptions for application rates.

“The recommendations are based off of crop removal and building soil fertility to a desired level,” says Skinner.

Once they have those two criteria, the Gambier, Ohio, company uses a worksheet to calculate application parameters.

“The biggest challenge is timing, because we always take our samples after we harvest,” notes Skinner. “We typically sample about half of our acres every year – about 1,900 acres. It takes a couple of days to get them pulled and sent in. We then wait a few days to get the samples back, which means we've lost a week when we could have been applying or chisel-plowing.”

Moving to what's new

Finding the right way to variable-rate nitrogen is the next experiment to push Hardscrabble Farms' soils beyond meager. In 2011, the Skinners invested around $12,000 in OptRx crop sensors. That figure included four sensors, harnesses, and a master module kit.

With two seasons on record, Skinner says the system is one of the bigger moneymakers they've invested in.

“We put the OptRx system on our sprayer last spring and used it in the summer of 2011 for the first time,” he says. “We liked it so much, we did almost all of our nitrogen application this year with the system.”

OptRx crop sensors, which Skinner uses in conjunction with their Integra display, measure and record crop data in real time using the reflectance of light shined on the growing plants.

Introduced by Ag Leader Technology in 2011, the system has the potential to save money by eliminating overapplication that often happens when applying at a flat rate. But it's also about increasing yields. The company says implementing the system can produce an average $25-per-acre profit due to yield boosts.

“We looked at yield data to see how the areas we used OptRx on performed,” explains Skinner. “I start out with a map in SMS, which is Ag Leader's software, and compare a 28% application-rate map with the yield map by laying one on top of the other. We can then see where our test strips are and can analyze the strip compared to where the OptRx ran.”

In the two years since they implemented the system, both have shown an increase in yield.

“The real wow was last year when we actually did the strip test and our average yield was a 13 bushel-an-acre increase with the OptRx and a slight savings of nitrogen,” he says.

In 2012, even with the drought conditions, they saw about an 11 bushel-per-acre rise. He feels testing didn't go that well, however.

“This year, we only had two strips we didn't run it on. I think those two strips are too narrow to do anything with,” he notes. “Of course, the drought this year affected that a little bit. But I don't think we had near the nitrogen loss we would have had in a normal year.”

The payback

For Skinner, the payback goes beyond improving the bottom line.

“Investing in the OptRx is partially about the savings and increasing yields, but it's also about wanting to be really good stewards of the land,” he says. “We don't want the nitrogen washing down into the creeks.”

While things have gone well, Skinner says there could be challenges.

“Height of the crop and trying to get it all done could be a challenge,” he notes. “We're waiting a long time to apply nitrogen. To do it properly, I start at the V8 stage, and I like to end at the V10 stage. We're getting into pretty tall corn by that point. So far, we haven't had a problem. But if we have a wet season, it's going to be an issue.”

With approximately $192,000 spent on nitrogen last year and a little over half of that (about 300 tons) going through the OptRx system, ensuring that every drop is placed where it needs to be is paramount to fine-tuning Hardscrabble Farms' nitrogen use.

“We are going to continue to make sure that nitrogen is where it needs to be to get the most out of the product and out of our soils,” Skinner says.


Changing the way things have always been done is never easy, especially when there's no credible data to back up that call for change.

“Prior to my return to farming, we had very inaccurate yield data and maps,” says Christopher Hudson. “I was not comfortable implementing variable-rate seeding (VRS) without at least three years of data.”

For the past four seasons, Hudson, who farms near Crawfordsville, Indiana, with his father, Curt, has been diligently gathering the data needed to transition to VRS.

But gathering accurate data wasn't the only change that needed to occur.

“To be honest, not until the past couple of years did my dad finally jump on board with the idea that there might be some value in variable-rate seeding,” says Hudson.

His dad's argument: You never know what the growing season is going to bring, so how can a prescription be written for your fields?

“In a really wet season, we can yield 20 bushels per acre better on our high ground than on our low ground,” says the senior Hudson. “Other years it might be completely opposite.”

So swinging populations to offset that variability wasn't particularly appealing to the elder Hudson. “You're normally not hurt by having an excellent population on a field,” he says. “I've seen too many times where it would have hurt our yields if I had backed off on population in the past.”

As a general rule, he says 30,000 seeds per acre isn't going to hurt them on their soils. While it might be beneficial for those with lighter soils to go down to 26,000 seeds per acre he's never seen the data to support that.

Even more reason to build historical data on their fields, because the more yield history there is, the more likely you are to find consistent patterns.

As his dad began to come around to the idea of using variable-rate seeding, the Hudsons experimented with 200 acres in 2012.

“We went to 20-inch rows two years ago and purchased a 48-row, 80-foot planter. It already had the factory components, like a hydraulic drive, to variable rate,” explains Hudson.

The one thing he did to make variable rating a little easier was to expand the role of their 20/20 SeedSense equipment.

“Before, it was just used as a management tool. Now, I've been trying to gear the 20/20 SeedSense toward actually running as much of the planting as possible,” he says. “I added the 20/20 RowFlow component to our planter, so when I run the prescription through the 20/20, I can adjust the rates as opposed to simply observing what is happening with the seed placement.”

Since it was really more about the experience this past year, they didn't swing the populations too high.

“A prescription that called for 42,000 or 44,000 seeds per acre wasn't something my father was going to be jumping for joy on,” says Hudson. “Our typical range is about 38,500 seeds per acre. I ran a couple of different strips up to 44,000 just to see if there was a response.”

To further their experience with VRS, over the past three years they have been allowing Monsanto to acquire their yield data for its Ground Breakers program.

The Hudsons recently applied to be a full participant in the program, which means they would provide inputs like field boundaries, yield data, and fertility results to their seed dealer. The dealer would then work with the Hudsons to select each field to enroll in FieldScripts.

A variable-rate seeding prescription by yield management zone is then developed, as well as a recommendation for the best hybrid for each field. The prescription is delivered through Precision Planting's FieldView app for the iPad and carried out using Precision Planting's 20/20 SeedSense monitor and planter control system.

“It would certainly almost be second nature to participate, because it would just be a matter of uploading the prescription,” Hudson says.

Hudson hopes to get their VRS ground up to 1,000 acres in 2013.

“I would like to see us split some fields, because there's no better way to have a comparison than to check on multiple fields,” he says.

“Variable-rate seeding is gaining traction, but it's still in the infant stages. It will come, though,” says Brian Sieren, marketing consultant/branch manager, Market 1, Inc. “I believe it is going to be the future because of seed costs and getting the most bang for your seed dollars. If an area only calls for and can handle 25,000 seeds, why plant 35,000 in it?”

In the end, it's about making the most out of every dollar spent on inputs.

“If there's profit to be made, I'm willing to take a look at anything,” says the senior Hudson. “And variable-rate seeding is just one of those things that I need to be looking at.”


For Grant, Nebraska, farmer J.J. Long, the first step in variable-rate technology is water.

“Where I am, water is the number one limiting factor,” says Long. “Everything else is secondary. I'm in a very arid area in southwest Nebraska. If I can even out my field by changing the way I water it, there's no point starting to mess with variable-rate seeding and fertilizer. In my opinion, I need to fix the water before I worry about anything else.”

If he still has problem areas or sections that seem to be outshining others, Long then goes back and looks at yield maps to evaluate whether or not he needs to adjust seed and fertilizer.

“Until I discover if I actually have another problem I need to address, I focus on making sure every drop of water I apply is where it should be,” he says. “I want to conserve the resource, and it also makes financial sense to be as efficient as I can with the water.”

He's accomplishing that by fine-tuning the way water is applied to his acres.

“I used to have 60- to 70-bushel swings from the top of the sandhills down to the bottom in the good soil,” he recalls. “Variable-rate irrigation is helping me make sure every acre gets the water it requires. What I used to consider to be the poorer ground might not have been that poor. It just wasn't getting enough water. It's really taken a lot of the variability out of the field.”

As part of the Republican River Basin, he says he's constantly in a state of back-and-forth with Kansas and Colorado over everyone getting a fair share of water out of the basin.

“The water table has declined, on average, about 1 foot each year for the last 30 years,” he says. “I've slowed the rate of decline by being more efficient with water because I know it's a limited resource.”

But it's also expensive to move water to where it needs to be.

“I pump from fairly deep irrigation wells. However I'm moving it – with electricity, diesel, or natural gas – the price is going up, and equipment is expensive.”

Even with irrigation efforts, he predicts that, because of the lack of rain in 2012, the water table will decline likely twice as much as it did the previous year. That's why investing in software to variable-rate his Valley Tracker system three years ago was so critical in managing every drop of water he applies to his land.

Previously, he was using a flat-rate pivot speed and applying the same amount of water to every acre. By implementing variable rate, he has the ability to apply water where it's needed most and pull back where it's needed less.

“My soils are very variable,” he says. “The lighter sandy soils never did get enough irrigation water, and some of the heavier soils were overwatered when I'd run on a flat rate. By varying the speed, I can give more water to an area of the field that requires more water and not overwater the wet areas.”

In order to transition to variable rate, Long turned to CropMetrics and its Virtual Agronomist software. Created by North Bend, Nebraska, farmer Nick Emanuel, the software is a whole-systems approach driven by data. The goal is to increase production on irrigated crop fields with soil or topography variability by applying the optimal application depths of water at the right time and place.

“The first step is to collect EM (electromagnetic) survey or Veris EC (electrical conductivity) data along with RTK elevation data,” says Chad Pfitzer, CropMetrics precision data specialist. “In order to give a true picture of what is happening in a field, the software needs to know the slope and water-holding capacity of the soil. If you don't, it's just a guessing game.”

For around $8 to $10 per acre, Long hired Midwest Independent Soil Samplers ( to conduct the survey.

Once data is gathered, it's then processed through the software, which develops a prescription. “It maps the soil water-holding capacity of the field by soil type. It then determines which area will need more water and which would have more water available so that it wouldn't need as much water,” Long explains.

The recommendation for Long's fields has his land divided into 60 different 6° zones off the pivot.

“The land is divided up into 6° pies, and each pie is getting a different water application rate,” he says. “I may have heavy and light soil in the same pie. CropMetrics is going to generate the best solution for that pie.”

After the initial start-up cost, Long says the fee to have the CropMetrics service is very low. “In the beginning, I probably had about $25 an acre into equipment setup and getting prescriptions written,” he notes. “After that, it is considerably less. Compared to the value of the crop I'm growing now, it's a pretty small expense.”

On average, corn yielded around 210 bushels per acre in 2011 and about 230 in 2012. “Most of my fields were the best they have been as far as yields, but I'm blessed with fairly good capacity in my irrigation wells because I watered a lot,” he says.

“We need this in American agriculture, particularly in irrigated acres and in a year like last year,” says Pfitzer. “If you own a pivot, why would you not want to be proactive when allocating the water? It's not about CropMetrics making money. We have scarce resources in water. Utilizing this program is a no-brainer.”

“The technologies I've seen and with the improvements in crop breeding, I think I'll be able to get to a sustainable point with my water table,” says Long. “I'll be able to irrigate crops and not deplete the water table. I'm moving toward that, and it's a process that gets better every year.”

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