When Bob Recker turned off every other row on his no-till planter, doubled the plant population and punched seed into Iowa soil, he crossed into the uncharted territory of 60" row corn. Recker was about to bathe his corn, and weeds, in sunlight, and attempt to maintain yield with only half the growing space.
According to Recker's triune agricultural gospel, or triple bottom line, every farmer must make money, grow food and take care of the soil — and he believes 60" row corn could improve all three facets.
Nature Abhors a Vacuum
In 2017, Recker planted eight varieties on 16 half-mile rows, each separated by 60" (almost five acres total). Accounting for the adjoining 30" corn planted at a 34,000 population, he doubled the 60" corn to a 68,000 in-row population to hit the same field population. The 60" rows were statistically equivalent in yield to the rest of the field.
Yet, as corn surges on sunshine, weeds thrive on solar power all the more: Nature abhors a vacuum.
“Yes, you’re giving weeds a great chance to get established in the open space,” he says. “You must have a residue base already in place or a good weed control strategy.”
For a farmer focused on growing corn, Recker recommends adherence to 30" rows, but for someone interested in taking advantage of the open row space, Recker urges consideration of cover crops, companion crops or grazing potential to use the space between the rows.
“Done right, you can get much healthier crop dividends, and a grazing opportunity may be the biggest bonus,” he says.
In 2018, Recker recorded 30 growers trialing 60" corn across nine states. He obtained results from seven plots without cover crops and five plots using cover crops. All told, the 12 plots showed an overall yield decrease of 5%, with a plus or minus of 10%.
The Right Combination
Recker isn’t wed to 60" rows; he’s wed to sunlight harvest. “If we find a cover crop or companion combination along with a yield increase, people will adopt any configuration,” he says.
How Wide Rows Improve Soil Health
Jack Boyer, in Tama County Iowa, planted four segregated strips of twelve 30" rows and four strips of six 60" rows. The overall results were equivalent, with the 60" rows yielding 205 bu. per acre and 30" rows at 200 bu. per acre.
In between the 60" rows, Boyer planted cow peas. When waterhemp emerged, he used a herbicide, killed the covers and replanted a multispecies mix after burndown, finally wrangling a degree of good weed control.
“Pick cover crops that come up and spread quickly to prevent weeds,” he says. “The 60" covers grew 10 times the aboveground biomass of the 30", and the nitrogen captured by the 60" was 10 times more than the 30".
My advice to other growers is to stay with 30", unless you are really interested in grazing cattle after harvest or improving soil health,” Boyer adds.
Opportunity For Livestock, Input Reduction
On 750 acres in Fayette County, Iowa, Loran Steinlage perpetually breaks the mold. He’s on a trajectory from interseeding to companion cropping to relay cropping, with an eye on space for livestock.
In 2017, he planted a plot with alternating corn rows of 30" and 60", with cover crops in between. He saw standard cover crop growth in the 30", but lush, knee-deep biomass in the 60". “If you’ve got livestock, 60" is the perfect opportunity to get a post-harvest grazing option very quick. We can maintain yield from what we’ve seen, and get good tonnage for livestock,” he says.
Steinlage is all no-till and 100% interseeded on corn acreage. Once again, in 2019, Steinlage is testing a 60" plot. “I hope to bring livestock back on the farm, but minimizing inputs is my focus at present,” he says.
Benefit of Weed Control Outweighs Yield Ding
Steve Walder grows a mix of conventional and organic crops in Vermilion County, Ill. He has giant ragweed control issues in organic corn and thought 60" rows could help. “I knew I’d be able to get between the rows much easier and have 50% fewer rows with weeds,” he says.
Walder planted 12 acres of 60" organic corn in 2018, and noted a 20% reduction in yield. In 2019, he tried five acres of 60" plots, with plant populations of 25,500 on 30" and 51,000 on 60". “This year, after harvest, I’ll know better if my yield comes close to the 5% average drop that others have seen.”
Walder plans to try 60" rows in 2020: “It takes multiple growing seasons to get a real idea. Long term, with the right hybrids and optimal population, and the right cover crops, that 5% yield drag may disappear.”