Converting a planter to twin rows allowed Mark Burrow to try the system without purchasing special equipment. The Altamont, Ill., farmer liked it enough that he’s modifying a larger planter to use this spring.  

Mark Burrow will be hitting the shop hard this winter. The result of his handiwork will have the Altamont, Ill., farmer seeing double this spring as he converts yet another planter to a twin-row configuration.

Burrow planted his entire 2010 crop with a twin-row planter he built last winter from a conventional John Deere 1790 12/24 split-row model. He’s back in the shop again because he had the opportunity to make a good trade for a new 16/32-row John Deere 1790.

Equipment alterations. Modifying last year’s planter was no small chore. Back rows were moved 7.5" to the right. This involved moving the main seed tanks, driveshafts and gearboxes. Burrow also added rectangular tubing to relocate planting units. The sprocket that drives the transmission was modified so the seed rate was correct for twin rows. The three-point-hitch drawbar had to be moved 3.75" in order to re-center the rows.

"This past summer I ended up making additional improvements by clamping two pieces of rectangular tubing to the existing center section unit mounts. It makes the conversion much easier," Burrow says.

This tweak to his old machine put six units on the center section and avoided the necessity of moving the seed tank for folding clearance. "I use longer drive cables on the planter units to eliminate the need to move the drive jackshafts," he adds.

Burrow sees twin rows as a way to increase corn populations without causing plant and root stress and without a major change in equipment. "Twin-row technology is allowing us to safely push our populations to the 35,000 plants per acre range even on lighter soils where a more typical population would be 30,000," he says.

In a twin-row configuration, corn is planted in paired rows, usually 7" to 8" apart, on 30" centers. The idea behind this system is to gain a more uniform spacing of plants, similar to narrow-row corn. It also allows growers to use the same corn head and other equipment set for 30" rows.

Research on the advantage of twin rows vary. Farm Journal Test Plots data from the past two decades has shown a 7 bu. to 10 bu. response to narrow rows (20" and twins) when compared with 30" rows. Farm Journal continues to test both corn and soybean twin-row production.

Yet in 2010, Pioneer Hi-Bred found no yield advantage to twin rows compared to 30" rows

in 179 paired on-farm research comparisons.

However, twin-row yields differed slightly across locations. Average twin-row yield responses ranged from 4 bu. per acre increases to 10 bu. per acre declines among replicated experiments in Illinois, Iowa and Minnesota, says Mark Jeschke, Pioneer agronomy research manager. He adds that the studies did not reveal any interaction between row spacing and planting population or significant differences in hybrid response to twin rows.

University of Illinois Extension agronomist Emerson Nafziger has data from 2008 and 2009 that shows no yield response to twin-row corn in a range of populations.

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