In 1996, Raymond Schlabs reduced the number of trips over his cornfields, cut down on weed problems, improved his irrigation efficiency and bumped up yields by a whopping 30%.
He did it by switching from 40" to 20" rows.
Schlabs and sons Tom, Kenneth and Ray farm 1,100 acres of center pivot-irrigated corn in the Texas Panhandle near Hereford. They also grow cotton and wheat.
Fields that yielded 140-160 bu/acre in 40" rows produced up to 230 bu in narrow rows two years ago. And last year, their average yield from 840 acres of 20" corn again topped 200 bu.
The Schlabs plant 27,000-32,000 seeds per acre with a Deere 71 Flex planter.
"That compares to 20,000 to 25,000 per acre for 40" rows," says Schlabs. "Our seed cost is $10 to $15/acre more, but with the much higher yields, we more than cover the added seed cost."
At planting, they also broadcast Surpass herbicide. Once planting is completed, the next wheels to roll over the fields, other than those of the center pivot, are on a combine.
"The herbicide provides early weed control," says Schlabs. "After the plants are from knee to waist high, the narrow rows provide enough shade to kill virtually any weed problems."
Schlabs says cultivation is unnecessary.
"We found we don't need it. We tried cultivating a few fields in 1996 and probably did more harm than good because the cultivator was too close to the roots."
With no need for cultivating, at least two trips through the corn are saved that would be needed on 40" and even 30" rows. Wide-row production also requires a lay-by application of a herbicide to hold weeds down, especially if rainfall is above normal.
"Trips cost us about $10/acre," says Schlabs. "We save that money. Just as important is the time we save. Most cultivating is needed when we're in the middle of wheat harvest."
The fact that soil remains moist beneath the jungle-like narrow-row corn while soil exposed to sunlight and wind is dry exemplifies how irrigation is more efficient in 20" rows.
"We have both half-mile and quarter-mile pivots," Schlabs says. "Drop tubes are mostly spaced 5' apart. Low-pressure nozzles are situated 21/2 to 3' off the ground. When we water, the water stretches farther in the 20" rows of corn."
Narrow-row corn and other crops are gaining popularity nationwide, thanks in part to the availability of planting and harvesting equipment to handle 15-20" spacings, says Tom Gerik, agronomist at the Texas Ag Experiment Station in Temple.
"John Deere, Case IH, Agco and Kinze have narrow-row planters, cultivators and corn headers on the market," he says.
Gerik, who is conducting research to compare 20, 30 and 40" rows, notes that 25% of the water from rainfall and irrigation can be lost to evaporation at the soil surface before a crop uses it.
"But by moving from 40" to 20" row spacing, growers can reduce evaporation losses by 50% or more," he says.
Midwestern narrow-row research indicates that yields increase by up to 10% when spacing is reduced from 30 to 20". Gerik and Clay Salisbury, another Texas A&M agronomist, believe that 20"-row corn under irrigation should easily average 10-15% higher in yield.
Preliminary first-year results of Gerik's research show a 13% yield advantage for 20" vs. 40" rows in irrigated plots at Amarillo. In non-irrigated trials in central Texas, the narrow-row advantage was 8%, says Gerik.
At both locations, the highest narrow-row yields came with high plant populations.
Schlabs and his sons are enjoying even better results. They expect to switch more of their corn to 20" rows in the next few years, and likely will invest more in narrow-row equipment. They also will increase plant populations each year until yields peak.
"Even if our yields aren't as strong as they were in '96 and '97, narrow-row corn is certainly an advantage over 40" rows," says Schlabs.