Growing soybeans without tillage can reduce production costs without sacrificing yield.
That was the main finding in a research and extension project in eight Midwestern states: Iowa, Illinois, Indiana, Ohio, Michigan, Wisconsin, Minnesota and South Dakota. The goal was to promote the adoption of no-till, improve variety selection by no-tillers, and identify lower-cost weed control programs for no-till soybean production.
Replicated on-farm trials in six of the states showed nearly identical average yields between no-till and conventional tillage (48.4 vs. 48.2 bu/acre, respectively). But average returns were $4.34/acre higher for no-till.
In five states, 21 comparisons were made between drilled (6-10" rows) and wide-row (30-35" rows) beans. On average, narrow rows resulted in 13% more yield and $30/acre more return than wide rows.
When results from all seeding-rate studies were compared, yields increased 2 bu/acre and production costs declined 50 cents/bu for every 50,000 increase in seeds per acre.
Variety performance was similar in both production systems, but performance under conventional tillage was a better predictor of performance under no-till than vice versa. The researchers point out that choosing varieties for emergence characteristics and disease resistance is more critical under no-till than under conventional tillage.
Many reduced-rate postemergent herbicide treatments provided satisfactory weed control and lowered production costs in no-till, narrow-row systems.
"Good timing on a half rate of post materials applied at the proper stage of growth will give you just as good of weed control as the full rate," reports Jim Beuerlein, Ohio State University agronomist.
"That's assuming normal weed populations, not weed patches that you've never been able to control. It's normal production fields where the weed pressure is not extreme."
The application should be made just before the canopy closes, making sure the herbicide hits the weeds, says Beuerlein.
(Ed Oplinger, University of Wisconsin; Keith Whigham, Iowa State University; and Jim Beuerlein, Ohio State University)