In southern Michigan, Farm Journal Associate Field Agronomist Missy Bauer conducted a three-year test plot looking at twin and 30" corn row spacings.
Test Plots continue corn row spacing study and how stress effects yields
More than 20 years of Farm Journal Test Plot research has revealed a thing or two about corn and soybean row spacings—and the learning continues.
In 2012, Farm Journal Associate Field Agronomist Missy Bauer wrapped up a three-year study looking at corn row spacings in the eastern Corn Belt. In central Illinois, Farm Journal Field Agronomist Ken Ferrie continued his work to learn more about how hybrids respond to plant populations, plant densities and stress of all sources.
Located across southern Michigan, Missy Bauer replicated row spacing test plots at three locations every year in fields varying from no-till to conventional tillage to irrigated.
"We launched this effort to see if my more northern location had any difference compared with the work done by Ken in Illinois," Bauer says.
Using a Great Plains Yield-Pro planter, Bauer’s test plot crew planted corn in twin rows (on 30" centers) and 30" rows at five populations: 29,000; 33,000; 36,000; 39,000 and 42,000 plants per acre. In-season stand counts and ear counts were recorded and each plot was harvested with a calibrated yield monitor and grain cart outfitted with scales. Then the data was analyzed by management zones.
In Bauer’s test plots it didn’t take long to realize that twin rows demand management changes.
"For example, with in-furrow starter fertilizer, the rate needs to be calculated per foot of row. So if you were applying 3 gal. in-furrow on 30" corn, you need to apply 6 gal. in-furrow for twin rows to achieve the same expected response," Bauer says.
In 2012, increasing the rate of in-furrow fertilizer from 3 gal. to 6 gal. in twin rows increased the yield response by 8.4 bu. When paired with 2x2 placement, the 6 gal. in-furrow rate outyielded the 3 gal. rate by 4.6 bu.
When it came to nitrogen management, higher populations also mean an increase in rates.
"We learned that when you have higher populations, you need to follow up with the necessary nitrogen," Bauer says. "If you are changing to twin rows from 30" rows you need to continue your nitrogen application practices, such as sidedress. Stay on top of your application window because twin rows will canopy and close faster."
In a tighter row canopy, especially with increased plant populations, scouting and disease management should be top of mind. Because the rows close sooner, more water is captured in the canopy and it’s slower to dry out, which sets the scene for disease.
At harvest, Bauer also recommends scouting for stalk quality. A fungicide can help improve standability.
"As we increase populations, we will have weaker stalk quality," she says. "Farmers should monitor fields to keep the plant standing for harvest."
- March 2013