"The narrow-row soybean concept is revolutionizing soybean production."
A pretty strong statement? Yup!
But Ellsworth Christmas, the Purdue University extension agronomist who said it, has plenty of company to second the motion - and statistics, too.
"I've been on the bandwagon for the narrow-row concept for years," declares Dick Cooper, USDA agronomist and soybean breeder at Ohio State University.
Adds Alan York, North Carolina State University extension weed scientist: "I'd say we are every bit of 60% drilled beans now in our state. And I don't see any reason that is going to change. In fact, I think it's going to continue to edge upward a bit, particularly with the entry of the Roundup Ready soybean system."
These scientists aren't necessarily pushing drills over split-row planters with 15" row spacings or the increasingly popular air planters or air drills. But it was drills, especially improved no-till drills, that launched and grew the trend.
Cooper cites these USDA-Ag Statistics Service data to back up their statements:
In 1988 in Ohio, 35.5% of the soybean acreage was drilled. In 1996, it was 69.5%. Indiana went from 16.3% in '88 to 68% in '96. Missouri grew from 19.7% in '88 to 53.1% in '95, dropping slightly to 48.4% in '96. Illinois went from 16.8% in '88 to 57.1% in '95 and 53.2% in '96. Minnesota was at 17% in '88, growing to 25% in '95 and 30.8% in '96. Iowa and Nebraska had no data for '88 but were at 28% and 24%, respectively, in '95.
"It has been a gradual but steady growth, a beautiful trend toward narrow rows," Cooper declares.
The drilled-bean trend may have peaked, Purdue's Christmas reasons. But not the total narrow-row trend.
There's nothing new about the yield advantage of narrow rows. Those figures appeared in many farm magazine stories years ago.
But, to refresh your memory, Christmas says Indiana growers expect about a 15% yield hike compared to 30" rows in the northern third, possibly the northern half, of that state. In the southern half, that drops to around 12%.
In northern Corn Belt states, such as Wisconsin, some studies have produced yield hikes of up to 18-20% for drilled beans. In areas far enough south to doublecrop beans after wheat, 18-20% yield increases over 30" rows are common, Christmas says.
With 15" rows, now possible with planters, there's a definite yield gain over 30" rows. On average, however, figure 15" rows will gain you two-thirds of the potential yield increase from drilled beans.
Besides higher yields, there's another definite advantage with narrow rows, especially with drilled beans, remind these scientists. That's better weed control from the quick canopy. With 7 1/2" rows, the canopy closes about 35 days after emergence with normal growing conditions, reminds Christmas.
Unless you have perennial weed problems, the canopy pretty well handles later-emerging weeds.
"For those farmers who have not considered it, and have adequate acreage to justify it, the purchase of a no-till drill should be a serious consideration," sums up Christmas. "I would put that pretty high on the management list. Certainly, buying into some way to narrow rows to at least 15" should be a no-brainer decision."