Agco’s single disc drill runs at higher speeds

Australian design | Heavy, high speed drill enables farmers to seed at 10 m.p.h.

WAHPETON, N.D. — The Sunflower 9800 Single Disc Drill introduced by Agco this summer is designed to work at speed.

“If you don’t have the power to seed at a minimum of 5.5 m.p.h., then you need a bigger tractor,” said Mark Wyrick, global product manager for Agco-Amity.

He said seven to nine m.p.h. is typical in fields where rocks are not an issue. When rocks are an issue, six m.p.h. is more appropriate.

Seed bounce is not the problem a person might imagine when running at those speeds. Wyrick said the 9800, one of the heaviest drills on the market, is designed for higher speeds and to keep the openers at a constant depth.

It’s called a single disc drill, but each trailing arm actually carries two sets of paired discs mounted six inches apart. There’s a nine inch gap on the field surface, which is not disturbed, and then two more sets of paired discs on the next arm. The patent refers to it as opposing single discs.

“I suppose you could also call it a paired row because the two discs work in conjunction with one another. They depend on each other,” said Wyrick.

“The discs fracture the soil and lift it. While the soil is lifted, the seed is placed into the soil. The soil then falls back over the seed row, preventing seed and fertilizer from bouncing out. Speed is an essential part of the plan.”

Wyrick said the angle of the discs is critical in lifting the soil and letting it fall back over the seeds. The concept, which was engineered and patented in Australia, is aimed at dry regions where farmers want an absolute minimum of soil disturbance, he added.

The disc on the left side throws soil to the right side, and a distinct line in the field delineates where the disc travelled. The field to the left of this disc is undisturbed.

The same action is repeated with the disc on the right side throwing soil to the left. The field surface to the right, outside the seed zone, is left untouched.

Amity Technology thought the drill would be a good fit for drier regions of North America.

It bought the patents and now manufactures the drill in the Agco-Amity joint venture factory in Wahpeton, N.D.

Amity field tested 25 units in 2008, fine tuning the geometry of the discs to suit heavy clay soil.

The discs have what amounts to five degrees toe-out. The leading edges of the two discs at the nine o’clock position are farther apart than the trailing edges at the three o’clock position.

The pair of discs are six inches apart, and their action creates a six inch wide cultivated seedbed for two rows of seed.

The discs also have three degrees positive camber, so the bottoms of the discs at the six o’clock position are closer to each other in the soil than they are at the 12 o’clock position.

“You can run granular fertilizer with the seed or you can add an optional mid-row bander for any form of nitrogen fertilizer,” said Wyrick.

“The mid-row disc is mounted ahead of and centred between each pair of discs. So you have nitrogen down the middle with a seed row three inches off to each side.”

Most drills run the gauge wheel next to or close to the opener, but the 9800 packer tires do double duty. They pack the seed row and hold the discs at the precise seeding depth set by the operator.

Locating packers on the trailing arm well behind the opener allows dirt coming off the discs to flow back to cover seeds without interference.

This design reduces the amount of crop residue tucking into the seed trench, eliminates sidewall compaction and leaves a six inch wide strip of black soil to promote soil warming.

There are no springs on the trailing arms. Instead, there is only one hydraulic cylinder for each arm. Depth control collars on those cylinders hold the frame at the correct height.

The discs seed shallower as the frame rises and deeper as the frame lowers. Seed depth goes from zero to three inches.

Down pressure adjustment is on-the-go from the cab. A display panel in the cab allows the operator to monitor toolbar down force.

The single disc drill was designed to be simple with a minimum of moving parts. The design of the trailing arm eliminates more than 75 percent of the moving parts normally associated with conventional single disc drills.

Two grease zerks on each arm require service every 25 hours. All bearings on the discs and packer hubs require greasing once a year.

“From the start, the Sunflower 9800 was intended to be a minimal soil disturbance drill for small grains in dry areas,” said Wyrick.

The machine is effective in high residue conditions, he added.

“We sell a lot of them in western North Dakota and up around Regina and west from there,” he said.

“Without changing anything, the drill works equally well in no-till, minimum-till and conventional tillage situations.”

Wyrick said the drill is a good match for the new 9900 series stainless steel air cart or it can be configured to work with any other brand of tank.

It can double chute with anhydrous ammonia, liquid or granular nitrogen.

The SF 9800 is available in widths from 30 to 60 feet. Power requirement is relatively low at seven to nine horsepower per foot of drill.

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