Editor’s note: This feature first appeared in the November 2013 issue of No-Till Farmer’s Conservation Tillage Guide.

The global push to increase crop production and keep pace with population projections underlines the importance for no-tillers to make every seed count.

Estimates predict that by 2050, the world’s population will increase by nearly one-third to reach 9.1 billion people, and agricultural demand is projected to grow by 70% to 100% by then, according to the USDA Economic Research Service.

Maximizing growing potential with corn and soybeans will be key, and one way no-tillers could do this is adopting variable-rate seeding, which precisely places the right type and amount of seed in the correct fields. This technology has the potential to not only boost yields but also save input costs.

Modern planters with newer technology lets no-tillers control, by the row, when and how much seed they place in the ground, based on prescription maps. And hydraulic, or newer, electric drives provide for faster and more efficient seeding.

“If you look at what’s going to propel yields over the next decade and beyond, more and more farmers will need to hone in on every section of land on a much more granular level than before,” says Rhett Schildroth, product manager with Kinze Manufacturing. “Optimizing every acre will require rapid changes in seeding and farmers will need the equipment and the data to create prescriptions.”

Chris Bettschen

"It would be difficult to get the benefit of variable-rate seeding without the right mapping..."- Chris Bettschen

In the past, seeding at a flat rate worked well for farmers and they were able to harvest a good crop, says Sean Arians, product marketing manager for Precision Planting.

But farmers need to challenge themselves to increase productivity and profitability, he says, and precision technology is allowing them to do so.

“We always talk about farming by the seed, rather than by the acre. What that means is being able to put the right seeds in the right place and increasing population on good ground, where the biggest return is going to be,” Arians says. “As we increase populations and manage varieties, increased yields will drive home paychecks at the end of the year for farmers.”

Profitable Populations

Two years ago, South Dakota no-tiller and strip-tiller Todd Boesen got his first taste of variable-rate seeding when he purchased a new16-row John Deere 1720 planter, equipped with Keeton seed firmers, pneumatic down pressure and variable-rate drive motors for seeding.

With soil types ranging from “gravel to good black dirt” across his 2,000 acres of corn, soybeans and sunflowers, Boesen long struggled with planting the proper seed populations to accommodate the variable soils.

Filling the Prescription
FILLING THE PRESCRIPTION. Developing a reliable planting map is critical to the success of variable-rate seeding. Topography for water flow, soil pH, organic-matter content and yield data are all part of the equation for building a useful prescription.

“I felt I was losing corn yield in my better soils because there weren’t enough plants there, and I was seeing many double ears,” he says. “In turn, I was also losing yield on the poor ground because the plants where too thick and I was getting a smaller ear.”

He started down the path to implementing variable-rate seeding on his farm by analyzing 2 years of yield maps collected through John Deere’s Apex farm-management software, cross-referencing the data with his soil-test maps. The comparison, combined with his own knowledge of his fields, gave Boesen a reference point on how different soils performed with a consistent rate of corn seed.

He used 22,500 seeds per acre as a baseline for check strips, then split fields into 4 zones and applied 4 different population rates of corn seed — 16,500, 20,500, 24,500 and 28,500.

“After doing some research, I thought it was best to jump populations between 3,000 and 5,000 seeds per acre, so I chose 4,000,” Boesen says. “What was surprising was that after the maps were generated, they showed that I was pretty close to 22,500 as an average seeding rate per acre, so my cost per acre wasn’t going to change all that much.”

While Boesen didn’t spend any less on seed, he did see a higher return population. On his poorer ground, where he planted 16,500 seeds per acre, he saw a yield increase of 10 bushels per acre compared to the test strip.

He lost 3 bushels per acre in his 20,500 population field, but gained 15 bushels per acre in the 24,500 field, and 35 bushels per acre in the 28,500 field, compared to the test strips.

“In the end, my variable-rate seeding gained me an average of 14.75 bushels per acre over a solid seeding rate of 22,500, and with no extra seed cost per acre involved,” Boesen says. “It was a very worthwhile project.”

Filling The Prescription

Last year, Boesen looked to replicate the results, but the drought took its toll on the corn crop and the test sites were harvested and chopped for silage.

But with the abundance of moisture in 2013, Boesen is more optimistic the results will be more on par with 2011. He’s also taken the step of hiring an agronomist to build prescription seeding maps.

"In the end, variable-rate seeding gained me an average of 14.75 bushels per acre..."
- Todd Boesen

Painting a thorough picture of a farmer’s field is a critical part of developing an accurate and useful variable-rate seeding program, according to Chris Bettschen, market development manager in Canada for Seed Hawk.

“It would be extremely difficult to get the benefit of variable-rate seeding without the mapping,” he says. “Most farmers know where the good and poor areas are on their land. But as they put in longer hours and seed more acres, mistakes can be made. To have automatic changes, you need those prescription maps to be made.”

One challenge for farmers to develop a reliable map is knowing what information to include or provide to agronomists.

There are no universal standards for creating variable-rate seeding maps because every farm or field is different, Bettschen says.

It’s wise for farmers to identify the most important aspects of their field before they invest in mapping, including topography for water flow, soil pH, organic-matter content and yield data. These criteria provide a good framework for building a useful prescription says Tom Evans, vice president of sales for Great Plains Manufacturing.

Saving Seed

Building an accurate map can lead to seed savings because higher populations will be planted in farm ground that can support it, he says. Prescriptions should rely on yield history, soil type and moisture content so proper populations can be recommended.

Electric Charge
ELECTRIC CHARGE. An emerging alternative to hydraulic planter drives are electric-drive systems which replace chains, sprockets and clutches, meaning less maintenance and the ability to change rates at higher speeds.

“Even if farmers are using slightly less seed, at $350 a bag that’s a major savings,” Evans says. “Variable-rate seeding can save you seed where you don’t need as much and cuts population on thinner ground. That also leads to yields as high or higher than you had before.”

This is a benefit Wray, Colo., strip-tiller Jerry Graham is seeing since adding variable-rate seeding technology 3 years ago. Graham is also co-founder of Graham Electric Planters, and his 16-row, twin-row Monosem planter is equipped with Precision Planting’s 20/20 SeedSense monitor and RowFlow rate/section controller. The planter is also equipped with Graham’s electric planter-drive system.

With sandy soils and variable pH levels throughout his 2,000 acres of irrigated corn, Graham says he’d struggled with productivity — especially on hilltops — and it was difficult to know where to cut population because residue tended to blow around during winter.

“We ran tests for a few years, and on every fourth pass with the planter we’d set a base rate of 34,000 seeds per acre,” Graham says. “When we harvested those hills, we didn’t see any increase in yields for that extra seed.

“We looked at the yield maps and they were about the same where we cut population, compared to where we left it high. That told me I was wasting seed there.”

Graham says he’s saved about 5% on seed costs, but it’s been more pronounced on hilly acres. Based on grid-sampling results, he cut populations on some hills to 22,000 seeds per acre in 2012, and it was a well-timed move given the drought.

“Even under irrigation, those plants were too stressed and it was a lot easier to keep fewer plants alive with water and residue during a rough summer, than had we planted a higher population,” he says. “We all want to go for that bumper crop every year, but in some cases you have to plan for the worst, Variable-rate seeding can help you do that.”

Electric Enhancement

One recent innovation that could help variable-rate seeding systems perform better is electric planter drives, which are gaining popularity in North America as a more efficient alternative to hydraulic motor drives.

Graham Electric Planters is one of several manufacturers that have developed or enhanced electric-drive systems as a simpler and faster way to precisely place seed.

“The electric drive is easier, because it replaces all the chains, sprockets and clutches which can wear out and need replacing, so there’s a maintenance savings there,” he says.

While hydraulic planter drives allow farmers to adjust seeding rates, electric drives are even more precise, says Arians. Precision Planting recently launched its vDrive electric drive system that works in conjunction with the manufacturer’s vSet seed meters and 20/20 SeedSense monitor system on planters.

“When you have a zone 100 feet by 100 feet or smaller, you’ve got to be able to change and adapt quickly. Hydraulic motors allow for that, but electric drives allow one row overlapping into another zone to plant the correct population,” Arians says.

Spacing Is Crucial

Proper seed spacing is also an important factor to achieve optimal corn yields, especially on variable soils and contours, says Schildroth.

On large contours, seed spacing can vary by up to 15%.

In 2013, Kinze launched its new 4900 planter, which is available with electric drive and a seed metering system that offers nearly 99% planting accuracy at speeds of 2 to 8 mph.

“When spacing is off, seeds can get so close to each other that they see each other as weeds,” Schildroth says. “With electric drive, farmers can slow down on inside rows and contours and have the same seed spacing as if driving in a straight line.”

Emerging Technology

For many growers, variable-rate seeding sounds like a great idea, but it’s still just that — an idea — in part, because of the financial and agronomic investment needed to implement the technology.

Schildroth estimates only about 10% of corn and soybean farmers have adopted variable-rate seeding. Farmers need to have a planter equipped with the technology, and also need a prescription map to realize the full potential of variable-rate seeding programs.

“There is still a gap in interest and implementation in the field. But we’re seeing companies start to fill the void of creating maps and that’s going to help adoption immensely,” Schildroth says. “But if you have a ground-drive planter, it’s going to be difficult — and probably not feasible — to do variable-rate because you’ll have to manually change gearing every time you want to change the application rate.”

It’s going to take time and education of farmers to embrace variable-rate seeding, but Bettschen sees a bright future for the technology. In 3 to 5 years, he expects that more planters will be manufactured “variable-rate capable.”

Whether farmers utilize the system remains to be seen, but the option will likely be more available for those that do.

“Even if guys aren’t sure they want to variable-rate themselves, or do it right at the time of purchase, they’ll probably make the investment,” Bettschen says, “because in 10 years it’s going to be extremely common.”