Central Washington farmers and ag equipment fabricators are moving ahead with promising results in a multi-year effort to design a new deep-furrow drill that plants through high quantities of residue in tilled summer fallow.
Four drill prototypes were tested during 2012, all pulled through 200 feet of 14-inch high stubble and 200 feet of 22-inch residue.
Pulled at three MPH, the drills matched the standard speed of using conventional deep-furrow units. The following is the latest report on performances of the test drills, with evaluations offered by project leader William Schillinger, superintend of the Washington State University Dryland Research Station in Lind, near the test site:
•WSU Lind HZ-type drill with 36-inch-diameter split packer wheels 16-inch row spacing, and a 30-inch diameter coulter: The coulters cut about half the residue and hair-pinned the rest, resulting in plugging. Offsetting the coulters two inches to the side of the seed openers helped considerably, but the drill plugged because there was not enough space between the in-line opener assemblies for soil and residue clearance.
•WSU Lind-HZ type drill with 36-inch-diameter split packer wheels at a 20-inch row spacing and 30-inch diameter coulter in front of each opener: Widening he row spacing made a big difference. This prototype had no plugging problems whatsoever. Since the coulter was two inches to the side of the opener, the hair pinning anchored the residue enough for openers to pass through with no problems. This prototype worked well in damp and dry conditions, and there was no bunching of residue in front of the openers.
•McGregor Company HZ-type drill with 36-inch diameter split packer wheels on a 16-inch row spacing, with offset spider wheels in front of each opener: The spider wheels do a good job of cutting and tucking residue to allow openers to successfully pass through, but the drill had considerable plugging problems with damp residue, although operating successfully under dry conditions. The 16-inch spacing with in-line openers does not leave much room for soil and residue clearance.
•WSU Lind 150-type drill with staggered hoe-type shovel openers on two ranks, and 36-inch diameter solid packer wheels on 17-inch row spacing: No plugging was found in the second year of testing this rig, credited to the staggering of openers in two ranks which left substantial clearance between openers and under the drill frame for high quantities of residue to pass.
After close studies of row spacing wider than the conventional 16- and 18-inch levels currently used in commercial machines, Schillinger found that very little grain yield difference resulted when using 18- and 20-inch row spacings.
"It is only when one widens rows to 22 inches and beyond that yield decline begins to occur," he says. "We have measured no significant difference in weed pressure among the 16-, 18- and 20-inch row spacings to date in these studies." This separate research was conducted over the last two years in eastern Washington at Lind and Ritzville.
To view some of the latest rig designs, go online and watch a short video presented by the project leaders here.
For more on this story, see the February Western Farmer-Stockman cover article.