By MATTHEW WEAVER
Testing will continue on a Washington State University deep furrow drill prototype after it passed a key milestone, seeding in heavy residue without plugging.
Bill Schillinger, director of WSU's Dryland Research Station in Lind, Wash., said his team is building a new frame for the drill.
The goal is to help dryland farmers direct seed wheat through thick crop residue. The residue helps farmers reduce soil erosion, but tends to plug current machinery.
WSU researchers found the best results in 2012 with a prototype similar to an International 150 drill. The drill had staggered, hoe-type shovel openers on two ranks and 36-inch solid packer wheels.
The frame was higher off the ground, with 27 inches of clearance while older models have 16 inches of clearance, Schillinger said.
Shanks on the older model have 19 inches in between ranks, while WSU's model has 26 inches.
"That's really the key, leave some room for the residue to flow through," Schillinger said, noting there was a lot of residue on the test site in Ritzville, Wash. "We had absolutely no plugging problems."
Schillinger said researchers were able to have 17 inches of space between seeding rows. The residue sloughed off, Schillinger said.
There's a chance the residue will fall onto a neighboring row, and be so thick it could inhibit seedling emergence, but Schillinger said that's a minor problem.
Schillinger is running row-spacing studies in Lind; Ritzville, Wash., and west of Pendleton, Ore.
Two years of testing have found 20-inch row spacing doesn't reduce grain yield compared to row spaces of 16 inches or 18 inches. Twenty-two inches or wider reduces yield, Schillinger said.
The researchers are adjusting seeding rates for spacing so there's the same number of seeds in a given area.
There's one more year of testing at the Lind station site. Schillinger is expecting thick residue again this year.
Schillinger said the ultimate goal is for a manufacturing company to build the drill and make it available to growers, perhaps with some USDA financial assistance or cost-share.
"When these drills go to the manufacturers, the simpler the better and the cheaper, too," Schillinger said.
The McGregor Co. recently sold its first deep furrow drill. The Colfax, Wash., company began working on a prototype after initial grower discussions in 2009.
McGregor is refining its design and production procedure to make the drill faster and easier to build, research field technician Paul Buchholtz said.