To expand their hands-on work with narrow row corn, Farm Journal Associate Field Agronomist Missy Bauer’s crew used this 40' twin row Great Plains planter.
An overview from our eastern Corn Belt plots
Corn Row Spacing
The Farm Journal Test Plots studied narrow row corn, including twin rows, for more than a dozen years in central Illinois with Farm Journal Field Agronomist Ken Ferrie. Expanding that work into the eastern Corn Belt, we launched a multiyear study to evaluate twin rows compared to 30" rows. These results fall in line with the previous work that showed a 7 bu. to 10 bu. increase for twin rows over 30" rows at the same population.
"At the same population, the twins outyielded the 30" rows by 9.5 bu. in 2010 and by 3 bu. in 2011," says Associate Field Agronomist Missy Bauer. "When population was dialed in to best match the row spacing, the twins outyielded the 30" rows by 13 bu. in 2010 and 6 bu. in 2011."
Narrowing the rows allows farmers to take advantage of the yield bump from increasing populations, Bauer explains. "We want to be cautious not to push population too far in narrow rows, especially with hybrids that have a lot of ear flex. In these cases, we may see yields go backwards. Hybrid selection and other agronomic practices have to be tuned to twin row production—it’s not just something to consider at planting."
Beyond hybrid selection, practices that require special consideration with twin rows include fertility management, insect scouting, disease management and variable-rate planting.
"Narrow rows are more efficient with plant spacing and water uptake, which means twins may handle higher populations," Bauer says. "The variability we see in soils emphasizes the potential of variable-rate population in twin rows to match the soil’s productivity."
As the motivation to control diseases and the concept of plant health become more widespread, farmers are asking if they should move or split their fungicide applications in corn to include a treatment at V5, which is early in the season with corn at five-collar development.
"With any fungicide application, farmers should keep in mind the disease triangle—host, pathogen and environment," Bauer says. "This, along with hybrid susceptibility, will help guide any application decision. But we have gotten more questions about fungicide timing at R1 [silking] and V5."
This past year was the second year of trials for Bauer, and field tests were conducted in irrigated corn-on-corn fields, which is the environment where you would expect a higher response to fungicide application. This was a split hybrid trial with one hybrid having a higher susceptibility score to Northern corn leaf blight, which was the primary disease challenge for that year. The fungicide used in the trial was Bayer Stratego YLD.
"In both years, when we did applications at both timings, the two applications did not have an additive effect to yield," Bauer says. "With single applications, our most consistent responses have been with R1 treatments, and the responses have been less consistent at V5."
In 2010, three of the four test plots had a yield response to an application at V5, and in 2011, one of the two test plots had a yield response to application at V5.
Bauer notes that a hybrid’s susceptibility and genetic responses to fungicide play a role in its timing responses.
"That said, if you are scouting early in the season and see diseases, you need to pay attention to thresholds and pull the trigger to spray," she says. "We’ll continue to look at these methods and learn more as we go forward."
Vertical Tillage for Soybeans
Many farmers no-till soybeans after corn, but Bauer often gets questions from farmers about whether adding a vertical tillage pass in the spring can improve yields.
"One of the things farmers struggle with is stand establishment in no-till," she explains. "Even in the 15" soybean rows, our goal is to plant in between the old corn rows, but the closer we are to the old row, the more of a struggle it can become. We’ve also tried to plant at an angle, which has helped improve things, but we still lose some stand when we cross the old corn row."
- Early Spring 2012