Keeping everything in harmony | Pulling a poorly adjusted disc harrow is like playing a violin that’s out of tune
Conquering B.t. corn root balls and stalks has become an industry unto itself in the past decade.
The older disc harrows and field cultivators just don’t have the weight or aggressive design to cut, slice and chop the residue of genetically modified corn, says Sunflower Manufacturing tillage specialist Larry Kuster.
“I can recall dozens of conversations with farmers complaining that their old tillage tools had been working just fine for years,” said Kuster.
“Then all of a sudden they started having trouble with Roundup Ready soybean stubble and B.t. corn stalks. That precipitated a complete revamping of our entire tillage line. We went heavier, more aggressive and bigger. It wasn’t just Sunflower. The whole industry had to upgrade.”
Discs are among the most significant advances. Heavier implements moving at higher speeds required better discs that kept their edge longer.
Kuster said standard disc thickness is now 0.25 inch, and most discs are boronized, making them far more durable than previous discs.
“Ingersoll developed the boron process for discs. We just don’t see issues with blades anymore, but they can go dull in time. So Ingersoll developed a grinder that puts a good edge back on the inside of the blade. They call it the Edge Care System,” he said.
“We have a new blade we call the Sunflower Sabre Blade. It’s exclusive to us from Ingersoll. We put it on our series 600 vertical till tool. Ingersoll calls it their SoilRazor. It has a serrated edge. Just like a good steak knife, it seems to stay sharp forever. People think it sharpens itself, but of course that’s not possible. It just seems like it sharpens itself.”
The SoilRazor has a rippled outer diameter that maintains a razor-sharp cutting edge. The flutes change shape as the steel in the blade begins to wear down.
The high points become the depressions and the depressions become high spots, always exposing a new sharp edge.
Ingersoll makes two versions of the SoilRazor. The VT is a vertical tillage blade that was developed in Hamilton, Ont., by Krause Corp. Most other vertical tillage blades have rounded edges that let residue escape, but the SoilRazor VT re-mains sharp so it slices the residue before it gets away.
The CT is designed with extreme clod-smashing abilities and extreme residue cutting characteristics in soft soil, which tend to move away under a disc.
Kuster said all types and all brands of cultivators have one thing in common: they are meant to run level front to back and level left to right.
He said this is important, whether farmers are managing residue or preparing the seed bed, and whether they’re using tandem discs or shovels and sweeps.
A poorly adjusted cultivator wastes fuel, contributes to erosion and is hard on the tillage equipment as well as the seeding rigs, sprayers and harvest implements that will be on the field next year.
“In fall tillage, you’re trying to achieve a smooth, flat field so the planter runs across the surface without bumps or jumps that shake the seeds off the disc,” Kuster said.
“Whether you have positive air like our White planter or a conventional vacuum, you actually can shake the seed off the disc if the field is rough. Then your singulation and spacing are out the window. The goal should be to achieve a consistent, level soil surface across the entire width of the machine, leaving no ridges or furrows.”
How a machine is set and used has a major impact on a farmer’s goals, he said. Setup also determines how effective the machine will be at cutting crop residue, sizing it consistently and mixing it into the soil to promote breakdown over the winter.
Although the owner’s manual gives all the information for proper machine setup, Kuster said people tend to put it off until it’s time to get in the field, even though it takes only an hour or two to do the adjustments on most machines.
He said farmers have so many acres they need to cover in the fall that they figure they can’t waste time adjusting the machine.
As a result, they do a bad job. Worse yet, they often do such a bad job they have to make a second pass.
The other excuse is that the machine was working well last time they used it so there’s no need to re-adjust everything.
Kuster said some parts wear and other parts become bent, and the machine may not have been working as well last year as the operator assumed.
He said farmers waste money when they put too much power in front of the tool. The general rule is eight to 10 horsepower per foot pulling a tandem disc harrow at five to six m.p.h., but the design of some new tillage tools allows faster ground speeds.
On the other hand, going faster than the recommended speed creates ridges and furrows and causes tillage tools to bounce, messing up the depth.
It’s important to adjust the tongue to match draw bar height to keep the tillage tool level and moving smoothly through the field. Components such as the draw bar and level lift receive extra down pressure if the tool is operated either nose down or tail down. The goal should be a straight line of draft to the tool.
Purging air from the hydraulic lines is the only way to ensure the wings stay level with the machine’s centre section.
Raise and lower the implement several times to allow the system to cycle fully while the hydraulics are connected to the tractor. Air is more easily compressed than oil, so air in the hydraulic lines can allow the wings to sag.
“If the operator is in a hurry and doesn’t bring it to a full lift, then the hydraulic system won’t phase properly,” Kuster said.
“It can build up pressure and that will mess up your side to side level. If the cylinder sags one-third inch, for example, that could allow the wing to drop approximately one inch. That is significant when the tillage depth you’re working toward is only five or six inches.”
The wider the machine, the more important it is to level it from side to side and from front to back so it works at a consistent depth without gouging or ridging. This allows the machine to handle crop residue with less bunching or plugging.
Height of the wings and centre frames should be consistent from side to side. Checking means lowering the tool to the ground and stopping the drop when the disc blades almost touch the soil.
Measure from the bottom of the frame to the centre of the pivot pin on the walking tandem, or the top of the wheel spindle if a single or dual wheel is present. The measurements should be the same.
To ensure the integrity of the centre lift components, check the centre-section wheels left and right. Now set the wings at identical depths by measuring from the bottom of the frame to the top of the wheel spindle or pivot pin of the walking tandem.
Adjust the measurements accordingly if wings wheels are smaller than the main transport wheels.
“The great thing about this method is the operator can use it at the shop or in the field. You don’t need a level slab of cement,” Kuster said.
As a preliminary adjustment, the fore-aft level should be set so the front and rear blades are an equal distance from the ground.
Travel 300 feet in the field with the tool lowered in the working position and then stop to see if the fore and aft level is still correct.
To be sure soil is flowing properly through the unit, inspect the soil at the centre rear where it’s returned by the rear gangs. It will produce a complete and level fill of the valley cut by the front gangs when the front to rear level is correct.
The rear of the tool is too high if a valley depression is formed by the soil and too deep if a ridge is formed.
Depth depends on field conditions and what farmers want to accomplish. A disc harrow is typically set to a maximum depth equal to one-quarter of the blade diameter.
Some implements have a single-point depth control with a hand crank that raises or lowers in half-inch increments with each handle rotation.
“When setting machine depth, be sure the machine carries some weight on the wheels, because the wheels are the base of all tool adjustments previously made,” Kuster said.
“When the tires don’t have some soil contact, control of the implement is lost.”
- Operate the tool with the wheels fully retracted and tires off the ground. Work the soil for a few hundred feet and allow the disc to achieve maximum depth. Then stop and lower the wheels until the frame begins to lift.
- Release the valve to stop the rise of the frame. Stop the tractor, but leave the tool in the ground.
- Adjust the single-point depth-control crank until the striker plate contacts the hydraulic poppet valve.
- Raise the tool until the audible click of the poppet valve engages, which stops the oil flow. The implement’s maximum depth is now set. Control of the tool is retained.
Setting the gauge wheels is the final step in setting up a tandem disc. Gauge wheels are critical on flexible tillage tools to prevent front-wing corners from gouging.
Those that have been set correctly should move slightly side to side when kicked. Measure to make sure the settings are the same for both gauge wheels.
Operators’ manuals will have full details for specific settings on specific brands and models of machine.
For more information, contact Kuster at 404-234-5258 or visit www.sunflowermfg.com.