Ohio no-tiller David McNeilan wanted to give his corn a little more room to breathe — and tap into more nutrients, moisture and sunlight. But he also wanted more plants per acre to chase higher yield goals.

The solution he’s working to perfect is a twin-row planting configuration that meets both goals.

A no-tiller for 15 years on his 1,000-acre farm near Celina, Ohio, McNeilan has been planting twin-row corn and soybeans for 5 years.

Although dry-weather challenges during that period have made a yield comparison with his previous system difficult, McNeilan likes what he sees.

“Higher populations are necessary if we’re going to continue to increase yields, but you can only put so many plants in a row before they start competing with each other,” McNeilan says. “Twin rows seemed like the best solution for us.”

His twin-row configuration is set up on 30-inch centers with 8 inches of spacing between the individual rows. That leaves 22 inches of spacing between each set of paired rows.

At a population of 38,000 seeds per acre, plant spacing within each row is about 11 inches compared to about 5½ inches for singular 30-inch rows. Seed placement in the twin rows is also staggered, forming a kind of triangular pattern designed to maximize room for root development and sunlight utilization, while minimizing evaporative moisture loss and weed growth.

The twin-row concept of giving corn more room to grow also results in better land utilization. At a population of 38,000 seeds per acre, single-row corn utilizes approximately 14.5% of an acre compared to 45% for twin-row corn.


011_DavidMcNealan_LA_0713-1-of-1-copy.jpgSo far, yields have been comparable to the previous 30-inch row system. But when dry weather compromised yields in his area last year, McNeilan says his twin-row yields held up better than most.

“I was tickled with it,” he says. “We had some yields in the 120- to 175-bushel-per-acre range, when there was a lot of corn in the county that was 40 to 50 bushels per acre.

“I don’t know if I can attribute all of that to the twin rows, but I think the plants had more root mass and the quicker canopy may have helped conserve moisture at the right time.”

McNeilan, who says “good year” corn yields are 175 to 200 bushels per acre, believes another reason the twin rows haven’t shown more of a yield advantage on his farm yet is inadequate nitrogen.

“We were trying not to spend the extra dollars on nitrogen, but I think we’ve been shooting ourselves in the foot,” he says. “We’ve had more plants out there, but no more nitrogen than we had at lower populations. This year, we increased the nitrogen by 10% to 15%.

“We have had some dry periods this season that probably took the top off of yield potential, but I think we’ll still have some pretty good corn. So this is really the first year we’re expecting to see the twin-row benefits in terms of yields. This year, I have the best-looking corn I’ve had in 5 years by far.”

Getting Started

Already interested in twin-row possibilities, McNeilan found himself dealing with some planter issues in 2008. He set his drill to plant twin rows on 6 acres as an experiment, knowing that it wouldn’t be a perfect situation.

“I just wanted to see what it would look like,” he explains. “And I wanted to make sure I could sidedress the twin rows and harvest without any problems.”

That experience prompted him to invest in a Great Plains twin-row planter.

After 5 years of use, he is replacing that planter with basically the same model — a Great Plains Yield-Pro 1225A, which is 30 feet wide with 24 row units.

As a no-tiller, the only modification he’s made to the bulk-fill planter is to add Martin floating row cleaners.

McNeilan especially likes the planter’s curved-tooth spider wheels for breaking sidewall compaction, while closing and firming the seed trench. The planter also has drag chains behind each closing wheel.

Each row unit has a meter to space and singulate seed drop. That allows McNeilan to set each of the twin rows separately so that the plants are offset to maximize the root-access area. The planter-tractor configuration also results in no wheel traffic over any of the rows.

“It’s easy to do,” he says. “You set the sprockets to corresponding numbers and you get very accurate placement. One of the twin-row units drops a seed and, 4 or 5 inches farther on, the corresponding unit drops its seed.

“That’s important in this twin-row system because the staggered placement is kind of like tricking the plant into thinking there’s a skip, giving it more room to access water, nutrients and sunlight.”

More Plants Per Acre

Before switching to twin-row corn, McNeilan was planting 30,000 to 33,000 seeds per acre. He’s increased that to 38,000 seeds per acre — up to 39,000 if he can get the planter into the field early enough in the spring.

He believes that his stand is at least as good as traditional 30-inch rows, with possibly less of a drop between the planted rate and final stand.

“It’s all about the opportunity to get more ears per acre,” he says. “In regular 30-inch rows, you can only crowd so many plants in there. I think if we’re going to make significant yield progress, we’re going to have to have more plants in the field.

“When the corn is coming up, it looks like you have a poor stand until the corn is about knee-high, even though there are actually more plants out there. That’s just because each individual plant has more room around it — more room to grow.”

McNeilan says he considered going to 20-inch-row corn, but opted for the twin-row approach because of the equipment changes narrow rows would require.

“Twin rows made more sense to us and I don’t see myself switching out of that system,” he says. “I’m pretty happy with it and we’ll continue to improve on it.

“I’m looking at going with variable-rate planting, too. I’ll probably end up with about the same number of seeds for a field, but I want the ability to back the population off on some of the lighter soils by 1,000 or 2,000 seeds and put that seed on the darker soil where it has the chance to perform better.”

McNeilan, who plants Beck’s Hybrid seed corn, takes the twin-row environment into consideration when he makes his hybrid selections.

He prefers to go with flex-girth and flex-length-type corn hybrids that have the growth potential to respond to the additional nutrient and water access provided by the extra space.

“I want the opportunity for a bigger ear, if the potential is there,” he says.

Fertility Choices

Dry urea with a stabilizer and ammonium sulfate is applied to corn ground just ahead of planting and incorporated to a shallow depth with either a vertical-tillage tool or Phillips harrow.

About half of the nitrogen goes on as a sidedress application. Because of the twin rows, McNeilan does have to apply 28% a little early — perhaps 2 weeks sooner than he would with single-row corn. Because of that, he adds a stabilizer to keep the nitrogen available for a longer period of time.

McNeilan, who began grid sampling last year, applies phosphorus and potassium according to soil tests. Applying poultry litter, however, has given him more than adequate levels of both nutrients in most fields.

“We used poultry litter for several years, especially on land where we wanted to build phosphorus and potassium levels,” he says. “We haven’t needed to use it lately, but it was a very economical way to build fertility.”

McNeilan also believes that the poultry litter, in addition to cover crops and no-till, has helped significantly build soil organic-matter content.

“We had one farm where the soil organic matter was about 1.5% about 10 years ago and now it’s up in the 3% to 3.5% range,” he says. “I think the more we use cover crops in conjunction with no-till, the more we’ll see organic-matter content continue to rise.”

More Twin-Row Benefits


Even though recent dry summers have eaten into yield prospects, McNeilan has observed some important differences in his corn plants.

“I have noticed that the corn has thicker stalks and larger root balls,” he says. “It’s hard to say what that translates into in terms of yields, but it tells me those plants are healthy and doing well.”

Thicker, sturdier stalks, he adds, should also help him have fewer standability issues under poor environmental conditions.

With more and bigger plants, more residue is also created. That hasn’t been a problem at planting time, and McNeilan says his six-row Case IH 5088 combine does a good job of evenly dispersing the additional residue at harvest.

“The twin rows pretty much harvest like single rows on 30-inch spacings,” he notes. “The combine snouts just crowd the two rows in just a little bit from the outside and it works just fine.”

Soybean harvest, for which McNeilan uses a draper header on the Case IH 5088 combine, has also been problem free. Although he normally employs a corn-soybean rotation, the few instances in which corn followed corn created no residue management problems, either, he says.

Additionally, McNeilan says the row canopies over about 2 weeks sooner than his previous single-row system. That can save him an additional post herbicide treatment, he says.

All of his agrichemicals are custom-applied. If there is a field with significant weed escapes after the pre-emergence burndown and residual herbicide application, he has the applicator run 90 degrees to the row to lessen wheel traffic over the small plants.

Although McNeilan expects to see the biggest yield impact on corn, growing twin-row soybeans enables him to use the same planter, although he hasn’t significantly increased his soybean planting population of 175,000 to 185,000 seeds per acre.

He does believe, however, that the twin rows help increase air movement between the soybean plants and may help avoid some disease problems.

Cover Crop Balance

After corn harvest, McNeilan makes a pass with a Great Plains Turbo Max vertical-tillage tool prior to drilling cereal rye. He’s previously used a Great Plains Turbo Till and a Case IH 330 Turbo and liked features of each.

There were times, however, when he felt the Turbo-Till moved too much dirt, while the 330 sometimes didn’t move enough. The Turbo Max, however, allows him to adjust gangs to be a little more — or less — aggressive.

Going across corn stalks in the fall, McNeilan likes to angle the shanks a little bit more compared to spring vertical tillage. The somewhat more aggressive action, he says, puts a little more soil on the residue.

“I just go in an inch or so,” he explains. “If we’re able to drill cereal rye, we have a little better seedbed. If we don’t, we help the residue break down a little faster.”

A day or two after the vertical-tillage pass, the cereal rye is seeded with a 30-foot Great Plains 3000 HD drill on 10-inch spacings, which allows planting between the twin rows.

McNeilan normally plants a bushel, or about 56 pounds, of cereal rye per acre if conditions are decent, using more seed if he thinks getting a stand may be difficult. He terminates the cereal rye with a herbicide application right after soybean planting.

Although time and weather don’t always allow McNeilan to get as much of his ground planted to cover crops as he’d like, cereal rye generally follows corn and precedes soybeans.

After soybeans, he prefers to plant annual ryegrass, which has a shorter planting window and doesn’t get as tall as cereal rye, but produces large amounts of root mass.

McNeilan has been planting cover crops for the past 8 years. They have become more important, partly because wet falls, less profitability and vomitoxin issues have made soft red winter wheat a minor part of his cropping system.

He’s also planted radishes, winter peas and oats. The radishes work well in wheat stubble because there’s more opportunity for growth before winter. But since wheat has become a minor and infrequent player in his rotation, radishes have less utility, he adds.

Cereal Rye: A Mainstay

While McNeilan believes many cover-crop species have a place, he’s been especially pleased with the cereal rye.

“It leaves the ground so mellow that you really don’t need much down pressure to plant into it,” he says. “And I know it’s improving the biological activity in the soil. Where we’ve had cereal rye, the yields seem more consistent across the field. I don’t feel like we give up as much production on the lighter soil areas.

“Most of all, though, cereal rye does a great job of protecting my soil. Seeing eroded areas is a big pet peeve of mine, and it seems like we tend to get some heavy rains in the winter just as the ground is beginning to thaw.”

McNeilan adds that a few years ago, cereal rye planting was interrupted by the weather and, by spring, he had some that was knee-high and some that was 6 feet tall.

“It looked like a mess from the road, but we planted soybeans right into it,” he says. “We took our time, but it was no trouble at all. And those soybeans were some of the best we’ve had — they yielded around 65 bushels per acre.

“There was a lot of residue on the ground and I felt that really helped keep the soil cooler during the summer.”

Cereal rye is also easy to seed and easy to kill, McNeilan says, and it has a fairly wide planting window.

“Last year, I planted one field on October 13 and then it turned wet,” he explains. “We finally had a stretch of decent weather and the Sunday before Thanksgiving, I decided to plant another field. I figured I wasn’t going to get anything out of that seed if it stayed in the wagon.

“It germinated, and even though it looked a little thin in the early spring, it really started growing. I wish I’d planted a lot more than that 130 acres.”

Advice For Covers

For no-tillers who have yet to adopt cover-crop planting as part of their system, McNeilan has this advice:

“Just do it,” he says. “I put it off for years. I’d come home from a no-till conference with every intention of trying it and just put if off too long.

“For someone planting a cover crop for the first time, oats may be a pretty good choice. The seed is relatively inexpensive and it winterkills, so you don’t have to worry about termination. You won’t get as much residue as with cereal rye — and probably not as much other benefits — but it would be a great way to get a feel for cover crops.”

McNeilan may try something a little different this fall. He’s planning to have one of his suppliers, VanTilburg Farms (VTF) of Celina, broadcast some of his cereal rye. VTF converted a Walker 44 high-clearance sprayer with a 90-foot boom and 30-inch row drops into a highboy cover-crop seeder.

Since it’s a high-clearance machine, McNeilan would have the option to plant in a standing crop. After the seed is broadcast, he intends to follow up with a post-harvest, vertical-tillage pass to improve seed-to-soil contact.

He tried aerial seeding annual ryegrass and radishes last year and, while acknowledging post broadcasting conditions weren’t the best, he wasn’t pleased with the cost-benefit ratio.

“I think the problem was the soybeans were too green when we put the seed on,” McNeilan says. “On other farms, where soybeans were a little further along, they got a better stand.”

McNeilan would like to get more of his ground covered with something that benefits his crops.

“The ground will cover itself up with something, so it might as well be something that does you some good,” he says. “Right now, cereal rye is the most useful cover crop for us because it protects the soil, cycles nutrients, adds a lot of organic matter, conserves moisture and prevents weeds.

“We’ll continue to look at the benefits of other species, though.”

McNeilan considers twin-row planting and cover crops as further developments in his no-till system. He got started in no-till to reduce input costs and to better protect his soil — and to be more profitable.

“When we started no-tilling, I think we gave up some yield compared to a conventional-tillage system. But even back then, I think we were making more money because of reduced costs,” he says. “One of my goals is to leave the land better than I found it, but if you aren’t profitable, that’s not possible.

“No-till, cover crops, twin rows — they’re all tools that I believe can help me accomplish both.”