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Overlap Control Catches On

“ Getting the most efficient use from fertilizer inputs boils down to a simple formula: apply fertilizers from the right source, at the right place, at the right time and at the right rate.” That is a quote from the Manitoba-North Dakota Zero Tillage Farmers Association’s new publication, Beyond the beginning: the zero-till evolution.

But for those with irregularly shaped fields and very wide seeding equipment, getting seed and fertilizer down at the right rate everywhere will be difficult. Overlaps create areas with too much product, leading to green patches and downed crops. That complicates things during harvest.

According to one seed drill manufacturer, SeedHawk, those areas can account for to up to 10 per cent of some fields. Cutting off flow to overlapping drill sections could save a lot of money by avoiding wasted inputs, not mention it could translate to better crop stands.

Of course farmers in areas like those around Regina or Winnipeg won’t have the problem as severely as others do, but they can still benefit from overlap control technology. Even if a field is perfectly square, making the last pass may not require the full drill width. In those cases, farmers can stop product flow to the portion of the drill that doesn’t need it.


SeedHawk was the first to introduce the concept to the market a couple of years ago, using the trade name Sectional Control technology (SCT). This year the company has introduced some refinements and additional features its system, according to Kurt Raffey, SeedHawk’s sales and marketing manager. “We’ve added hydraulic drive motors and replaced our gearboxes,” he says. “It’s not ground drive; it’s a motor on each meter. It’s smoother. And for anyone who uses variable rate with prescription mapping, we’ve improved the timing of it.”

Farmers who purchase the SCT package for 2011 will also get a hand-held calibration monitor that can be taken to the seed cart. It can be used to transfer flow rate information back to the Raven Viper Pro monitor in the tractor that operates the system. Raffey says that will reduce the time it takes to adjust seeding rates.

Another manufacturer, SeedMaster, offers its own version of overlap control, which it calls Zone Command. This system is manually controlled from a switch panel inside the cab; the operator has to turn off product flow to sections of the toolbar. But that will soon change. The company is offering an electronic monitoring package on its drills for the first time this year, using a DICKEY-john system.

Company president, Norbert Beaujot, says the Dickey-john controller will eventually be able to automatically handle the Zone Command feature. Look for an announcement on that soon.

Morris introduced its first-generation overlap control system last summer. It uses two hydraulically-controlled gates to stop product flow to either half of the cart’s meter. And it, too, relies on manual control.

While both SeedHawk and SeedMaster’s systems will pull the unused openers out of the ground when flow is shut off to any section, the Morris system can’t. Pulling half the drill out of the ground would cause serious skewing.

“This technology is only the first stage of advanced overlap control,” says Randy Ellis, director of North American Marketing and Sales for Morris. A second generation system with more advanced features is already in field trials, but the company hasn’t yet announced a possible release date for it. The Western Canada Farm Progress Show is where Morris introduced the current version. So, be sure to look under their air carts at this summer’s event to see if there’s anything different. “It’s not too far down the road,” says Ellis.


Contacthimat [email protected]


Even if a field is perfectly square,

making the last pass may not

require the full drill width

About the author


Scott Garvey

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



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