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How The Cross Slot Opener Works

Cross Slots require seven to nine hp per opener on level ground, and up to 15 on steep slopes. In comparison, a test of four common Canadian double-shoot openers evaluated by the Alberta Ag Tech Centre required five hp or less.

Arguably, the Canadian Prairies are ground zero when it comes to the development of no-till seeding equipment. Local manufacturers of airseeders now export their technologies to the world. But we certainly weren’t alone in the drive to create a better no-till machine.

Among those working on seeder development in other parts of the world was a group of researchers at Massey University in New Zealand. They developed their own no-tillage, independently-linked seed opener designed to conserve moisture. It offers what the inventors call “ultra-low disturbance”. Today, they too are marketing their technology to the world, under the trade name Cross Slot.

“Cross Slot arose to eliminate the failures that often occur when

farmers attempt to use no-tillage in dry climates,” says John Baker, CEO of Baker No-Tillage Ltd., in New Zealand. “Its main claim to fame in this regard is that the opener harnesses the water vapour that all soils contain, even when they are very dry.” That improves the likelihood of germination because humidity around the seed is not lost.

To do that, the Cross Slot creates horizontal cuts on either side of a central furrow created by the disc blade. Seed is then placed to one side and fertilizer on the other, below undisturbed ground.

“Most other slots are either vertical in shape, or where they are horizontal, the residues are swept aside and do not form part of the slot-covering medium,” says Baker. This statement may spark debate from marketing reps of other manufacturers. And, he adds, maintaining a residue cover is essential in retaining humidity around the seed.

When it comes to dealing with crop residue, Cross Slot company literature says the openers have successfully seeded into the unchopped stubble of a 140-bushel-per-acre cereal crop, including directly through the un-spread windrows left by a combine.

Even though the openers use a disc to open a furrow, there is virtually no trouble with hair-pinning. That’s because the Cross Slot places the seed off to the side, far enough from any trapped residue to avoid the problem.

“This gives it the ability to handle virtually any type or amount of residue while still maintaining the ultra-low disturbance quality,” says Baker. “In many circumstances it returns 100 per cent of the residues over the slots.” The company’s sales brochure claims the typical amount of residue remaining is closer to 70 per cent.

“And the Cross Slot uses an automated system that ensures the opener maintains a constant seed placement depth,” explains Baker. “Because the soil is not tilled, it will naturally vary in hardness across all fields. Cross Slot has an automated system that changes the down force applied to the openers three times per second, in order to be sure that down force always matches soil hardness.”

Down force can go as high as 1,000 pounds, if necessary. Openers, can even be ballasted up to a maximum weight of 1,000 pounds each for improved

penetration in extremely hard and dry soil conditions. Optional suitcase-style weights are available for that purpose. Adding to that high force is the hefty weight of the openers, which average about 250 pounds each.

Most Canadian designs offer maximum trip pressure in the range of 450 to 600 pounds, which is usually sufficient. Under typical spring seeding conditions, the Cross Slots’ extra penetrating force likely wouldn’t be needed. However, it may help when tackling more difficult operations, like seeding directly into grass sod.

Cross Slots use two hydraulic cylinders, which work opposite to each other, to raise and lower them. But the cylinders’ connection is cushioned by compressed nitrogen to minimize ground shocks. The openers allow for 18 inches of vertical travel.

The company and many of its customers claim even rocky soil is easily handled by these openers. Their design actually forces rocks down into the ground, rather than lift them out; although with the heavy weight of the openers, high down force and faster operating speeds (up to 10 mph), working in rocky soils without damage may be something producers will want to see to believe.

And because the side blades actually rub on the disc, it can operate even in very wet soil conditions. But that friction combined with the weight of the openers demand a lot more horsepower from a tractor. On average, Cross Slots require seven to nine hp per opener on level ground, and up to 15 on steep slopes. In comparison, a test of four common Canadian double-shoot openers evaluated by the Alberta Ag Tech Centre required five hp or less.

RETROFIT EXISTING DRILL

Baker No-Tillage makes complete airseeders, but they also make retrofit kits, so producers can install Cross Slot openers on other air-seeder frames. “Retrofitting Cross Slot openers to existing tool bars is the least-cost option,” says Baker. That makes this the logical route for Canadian producers interested in adopting the technology, which is the way Baker’s sales into Canada have gone, so far.

What does that kind of retrofit cost? “In rough terms, a single Cross Slot opener complete with a share of the cost of the electro-hydraulic control system, ready for retrofitting to a 10-metre (33-foot) frame, is about $4,400 per opener,” says Baker. That number gets a little smaller as more openers are added, because the cost of the down force control system is spread over more openers.

The company has just opened a North American office to market their openers and no-till drills into the U. S. and Canada. Gavin Porter who runs that office, located in Pullman, Washington, says the design of the Cross Slots makes them one of the lowest disturbance systems available in the world. So the company will be focusing on that attribute in its future marketing efforts.

To find out more, check out the company’s website, www.crossslot.com,or contact Gavin Porter at Baker No-Tillage (USA) toll free at 1-888-663-7773 or [email protected]

Scott Garvey specializes in writing about tractors and farm machinery technology for publications in Canada and Great Britain. He’s also a former affiliate member of the Society of Automotive Engineers (SAE). He farms near Moosomin, Sask.

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Scott Garvey

Scott Garvey is a freelance writer and video producer. He is also the former machinery editor at Grainews.

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