Skipping rows has some narrow-row soybean growers skipping to the bank.
By leaving two unplanted rows with every planter pass, Jeff Sollars of Washington Court House, OH, saves seed costs at planting and assures 100% spray coverage.
The idea is simple. By leaving unplanted rows for sprayer wheels to follow, those unplanted rows act as wheel tracks. That prevents spraying gaps and yield loss from running down soybean rows during late-season spraying.
“The real value for our operation has been the convenience factor. We don't waste time — when it's time to spray we can see the row tracks and just go spray,” says Sollars. He farms 3,600 acres with his father, Frank, and two brothers, Brian and Mike. “I know the time we save has helped our bottom line even if we can't calculate the exact amount.”
However, Jim Beuerlein, an agronomist at The Ohio State University (OSU), has calculated the economic return.
“It actually can end up quite a bit cheaper to skip those rows,” says Beuerlein. “For a 30-ft. drill, it costs a grower a net $1.46/acre to leave the skip rows. But if he has to spray late and run down two rows he already paid to plant, it can cost anywhere from $3.38 to $8.13, depending on the size of the sprayer.”
However, Anne Dorrance, OSU plant pathologist, cautions that skip rows are not for everyone.
“This is for high-yielding fields where the beans get really tall — above 36 in.,” she says. “If you've got shorter beans, lower production or a 30-in row system, it's not for you.”
Although skip rows have been used in Ohio for more than 20 years, Beuerlein says skip rows could become popular in other states as more farmers spray for Asian soybean rust and soybean aphids.
University of Illinois Entomologist Kevin Steffey says skip rows would work well in his state for growers using narrow rows and ground sprayers. In fact, Illinois has seen nearly a 30% increase in 15-in.-row soybean acres since 1997, according to the Illinois Agricultural Statistics Service. However, that state has a big aerial application industry. Steffey cautions farmers who usually rely on aerial applicators to scrutinize the numbers closely.
“For those convinced ground spraying is the way to go, skip rows would make sense,” Steffey says.
If growers end up spraying once for aphids, twice for rust and make herbicide applications, skip rows will probably become commonplace, says OSU's Beuerlein.
“Until now, the chance of having to spray in late July or August has probably been 20% or less, so people have taken the chance that they'll have to run over some rows,” he says.
With the new threat of Asian soybean rust on farmers' minds this year, skip rows can really be a benefit, especially for farmers relying on commercial applicators, says Dorrance.
“Skip rows will be critical for high-yield, narrow-row production systems, especially if rust appears very late in the season where we'll need late growth stage applications — between R4 and R6,” she says.
The economics can be a bit cumbersome, but Beuerlein has created three tables designed to calculate the costs of implementing skip rows on a per-farm basis.
The Sollars save nearly $4/acre using skip rows, according to Beuerlein's tables, which you can find on the Web at agcrops.osu.edu/soybean.
Here's how it works: Beuerlein first calculates the cost of running down two rows if a late-season sprayer application is needed. Costs are calculated at different dollars per bushel and spray boom widths. For example, using an 80-ft. boom coupled with $6.50/bu. beans, the Sollars would lose $5.07/acre.
Beuerlein next figures the yield and income lost by leaving unplanted rows. He calculates that a farmer not planting two rows with each 40-ft. drill pass gives up $2.35/acre in yield with $6.50/bu. soybeans. But, the Sollars would also save $1.24/acre in unplanted seed — assuming a $40/acre seed cost.
The final calculation combines the first two figures and determines the total cost of skip rows for different combinations of drill sizes (15-40 ft.), seed costs per acre ($25-65/acre) and grain values ($5-7.50/bu.). Total skip row implementation cost for the Sollars was $1.11/acre. But compared to the $5.07 in losses they'd incur if they needed to spray and didn't have skip rows, they pocketed $3.96/acre.
“We love it because we don't have to depend on foam markers, a lightbar or GPS,” says Sollars. “When you turn the sprayer around, you know right where you need to go.”
Some growers think starting a skip-row system is difficult, but Beuerlein says, “It's actually simple. Coordinating sprayer and planter size is the most complicated part. You need to have a sprayer that covers one, two, three, four or five planter passes.”
After that, it's a matter of planning the spacing of the skipped row to fit your sprayer's tire spacing.
“And if you're lucky enough to have a sprayer that is exactly three times the width of your drill, you just follow every third drill pass,” he adds. “You'll start with the second set of skips and then drive on the fifth, the eighth and so on.”(See chart below)
Beuerlein says that if you have a sprayer that's two or four times the size of your drill, you'll need to switch off a fourth of the boom on the first round and then use the whole boom for the rest of the field. That will line up the planter skips with the sprayer wheels.
“With modern spraying equipment, turning off nozzles is really easy to do,” says Beuerlein. “Most sprayers now have multiple nozzles; you can just twirl the nozzle around and you'll have a blank.”
The Sollars, on the other hand, didn't like the idea of wasting time turning nozzles on and off with their 80-ft. sprayer to accommodate their 40-ft. planter passes. Instead, they used a little ingenuity and changed the planting pattern of their fields.
“We have the spacing figured out so we don't have to change anything once we drive into the field,” Sollars says. “We plant the first round of end rows clockwise, then the next round counter clockwise and it all works.” (See diagram below.)
The Sollars modified their Kinze twinline planter by hanging an additional row unit on the left side of the toolbar while removing the unit third from the left end. With those modifications and a simple extension of the row marker, they were set for planting skip rows.
It can be even easier than that with a grain drill, says Beuerlein. “The easiest way to make skip rows is to plug two of the seeding units in the drill.”
If you're still concerned about the logistics and potential yield loss of leaving unplanted rows, Ron Hammond, OSU entomologist, says to consider that soybeans compensate for skipped rows by branching and leafing out.
“But if you run over rows late in the season, the plants won't be able to fill in the gaps,” Hammond says. “With skip rows, the four rows bordering the skips branch out and compensate somewhat in yield.”
Sollars says he increases the planting rate of rows adjacent to the skip by 10% to close the yield gap from skipped rows even more.