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When baler marries combine…

LOUISVILLE, Ky. – The prospect of selling straw at $60 to $70 US per ton didn’t occur to Graham Shields until his Bale Direct System was well on the road to completion.

His initial goal was to control a herbicide resistance weed species that was creating havoc in his area. However, the tool he devised to control that weed problem ended up generating significant unanticipated profit for the farm.

Shields, managing director of the 35,000 acre Glenvar Pastoral Co. in Western Australia, solved the headache by removing the offending seeds from the field at harvest.

His patented device joins a big square baler to the back of a modern high-performance combine. The key component is a conveyor system that ensures 98 percent of the weed seeds are baled and removed from the field. That number is confirmed by Michael Walsh, an Australian researcher specializing in herbicide resistance.

“We already knew that modern combines are extremely efficient at collecting weed seeds at the header and then separating them from the grain,” Shields told agricultural engineers at the International Conference on Crop Harvesting and Processing in Louisville, Kentucky, in February.

However, once the seeds are part of the chaff, they are typically spread on the field again to continue causing problems.

Shields said farmers miss a significant weed control opportunity when they knowingly let those weed seeds and volunteer crop seeds escape.

The conventional harvest system not only perpetuates the reliance on chemical weed control but also incurs extra costs when managing field residue and trying to seed through it for the next crop.

If necessity truly is the mother of invention, she was speaking loud and clear to Shields 20 years ago when he faced his weed crisis.

A combination of invention and innovation were necessary if the farm was to continue producing wheat.

The problem weed was rye grass.

It wasn’t a big problem as long as the farm stayed in the traditional Western Australian rotation of sheep for three years followed by one year of wheat.

However, the introduction of disc and narrow knife seeding equipment in 1981 allowed the farm to go into continuous no-till cropping without the sheep. Rye grass began taking over.

“By the late 1980s we already had herbicide resistant rye grass in our paddocks. By the early 1990s it had become a huge problem. We were seeing drastic yield reductions,” Shields said.

“Something had to be done if we were to continue farming this land. Burning the chaff didn’t work. To get the fire hot enough to kill the rye grass seeds, you had to burn on a really hot, dry day. Fires got out of control. Plus we were experiencing wind erosion on the areas we had burned.”

Redekop chaff carts imported from Saskatchewan were the first step toward solving Shields’ problem. He had read about carts that collected chaff directly off the combine and decided to try them in the early 1990s.

At the time, he wasn’t thinking about selling chaff into the feed market. He just wanted to collect and burn weed seeds more efficiently.

“We already knew we were doing a good job of getting all the weed seeds into the front of the combine. If we could only find a way to dispose of them, our problem would be solved,” he said.

“So we bought three Redekop chaff carts from Canada. That allowed us to effectively collect nearly all the rye grass seeds, but burning was still a problem. Fires would still get away from us. Wind erosion took a toll. Plus we realized we were wasting good, valuable crop residue.”

The next step for Shields was to build his own self-unloading chaff carts. He worked with that idea for two years, hoping to find a way to handle the chaff so it could be removed from the field.

“But the main characteristic of chaff is that it’s very light and fluffy and there’s a lot of air space. It’s impossible to handle large volumes. So we ended up still having to burn chaff in the field. We weren’t any further ahead with the self-unloading carts. We realized it was not practical to continue down that road,” he said.

“At that stage, we decided to try baling all the chaff and straw together, directly as it came off the combine, before it had a chance to touch the ground.”

Shields said the new plan gave him a better chance of capturing all the weed seeds and also eliminated field operations because the combine operator also operated the baler. The only remaining field operation was to collect bales.

He reasoned that if the conveyor system could efficiently move crop residue from the combine to the baler without losses, the weed problem would be solved.

The byproduct that Shields had not anticipated was a high value feed material for the livestock industry. Each bale contained straw uniformly mixed with higher protein material such as broken grain and weed seeds.

An added benefit was that the chaff helped pack the bales tighter. Denser bales are generally more weatherproof and easier to handle.

“The protein level is one percent higher than straight baled straw, but the factor which the feed mill likes the most is they know they always get clean bales from us,” Shields said.

“The straw and chaff never touch the ground. There’s no rocks or stones or kangaroo carcasses. It’s extremely clean compared to raked straw or windrowed straw.

“That adds value to our product. The feed mill pays us a premium. We’re selling bales for $60 to $70 US per ton sitting in the field.”

Shields said the ratio of grain to straw is usually 1:1 in most wheat fields. A farmer who produces one ton of grain per acre can expect to bale one ton of chaff and straw per acre.

“Straw has become a very profitable enterprise for us. It has turned this problem into profit. And it has solved the weed problem. Any weed seed that gets into the header on the combine ends up in a bale – not just the rye grass but any and all unwanted seeds.”

Dedicated no-till farmers would say this creates another set of problems because it removes too much organic matter from fields, leaving only standing stubble.

Shields said that doesn’t appear to be a problem. Wind erosion had been worse when he had numerous burn spots scattered around a field.

“We leave six inches of standing stubble. Even with the residue baled and taken away, that’s enough standing stubble to prevent wind erosion,” he said.

“With the surface residue gone, it’s very easy to seed the next crop into standing six inch stubble. And the no-till seeding equipment we have leaves nearly all of that stubble standing so it provides protection to the new germinating crop.”

The Bale Direct System mechanically and hydraulically links the combine to the baler and channels all chaff and straw into the baler.

The kit includes a drawbar, which runs all the way to the front axle of the combine and hangs suspended from the rear of the combine.

The baler attaches to this combine drawbar with its own modified drawbar hitch. The regular pickup on the baler is removed.

The baler can be detached from the combine in about two minutes and converted back to a tractor pull unit in about four hours. The combine can also be converted to its original mode of operation by bolting the original pieces back into place.

The hydraulically driven conveyor collects everything from the threshing unit and transfers it straight into the baler. A housing surrounding the conveyor is designed to ensure no material is lost.

Producers can remove the regular straw chopping, straw spreading and chaff spreading mechanisms from the combine.

Power originally used for that equipment is used to drive the conveyor and the baler.

Shields said he doesn’t know how much power he saves by not running the residue management machinery, but it seems to work out about even. The power he saves is about the right amount needed to run the Bale Direct System.

“For example, we know that the Claas combines we use have a power allowance of 85 horsepower for just the straw chopper by itself. That factor alone accounts for more than half the power we need to run our Bale Direct System,” he said.

“With our kit, we add a 140 hp hydraulic pump that runs off the main driveshaft of the combine. We have large hoses to the conveyor and back to the hydro motor, which drives the baler.”

Shields said he initially bought Claas combines because they were the only machines with 400 hp. Now that other brands have matched that level, any Class 8 or Class 9 machine should have enough power.

He said one of his latest conversions is on a New Holland CX880 European model combine. He has been using Hesston and Claas Quadrant balers but said the system will adapt to any brand and model.

Shields emphasized that the front axle is the only pick-up point on a combine strong enough to pull a baler, which is where his drawbar attaches.

“Another essential option is auxiliary rear wheel drive. When you’re pulling an extra nine tons of equipment, it must be attached to the front axle and you must have the rear drive to get enough traction. There is no other way this can work.”

Shields said that in six years of operation, the three Bale Direct Systems he uses on the Glenvar farm have given no problems. The same is true of the custom units he has sold to other Australian producers in recent years.

The kits are built in Australia. A complete kit, with everything fabricated to bolt directly into a specific combine, sells for $70,000 US.

“This started out strictly as a weed control device, but with the other economic benefits and now with the interest in biomass, residue collection becomes more viable every year,” he said.

“And that’s why I’m in North America this winter. I’d like to see if there’s interest over here in baling directly off the combine. If there’s a Canadian wheat grower on the Prairies interested in trying this, I’d certainly like to hear from him.”

For more information, contact Shields at or visit

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