When a field requires more than a harrow

The new Schulte Soilstar DHX0600 uses a disk and harrows to work up the top two inches and create a solid seed bed

REGINA — A post-harvest heavy harrow pass is standard practice for many prairie producers.

It helps spread crop residue to prevent it from clogging seeders in the spring, and it can promote germination of weed seeds just in time to be terminated by freezing temperatures.

There are years, though, when a fall pass with heavy harrows does not adequately deal with excessive crop reside, or hard ground conditions prevents any mixing of soil and straw.

These are the conditions the new Schulte Soilstar DHX-600 was designed to address.

“We’re going about two inches (deep) with the disk and the harrows to kind of get the top two inches mixed up to create that nice seedbed,” Todd Hoffman, president of engineering with Schulte, said at Canada’s Farm Progress Show in Regina.

He said there’s been an increase of finely chopped straw discharged from his combines and traditional harrows no longer adequately drag and mix the material into the top few inches of soil.

“So we’re trying to develop something that can work with the ground and help to mix that chaff and the straw with the ground a bit. So that you can incorporate it, and it warms up the ground faster in spring time and help that water infiltration,” Hoffman said.

The disk harrow has two rows of coulters with 7.2 inch spacing.

“You can engage those coulters, they go into the ground and size the material and mix ground with that chaff. They don’t do a full tillage pass. They break the ground up enough that when the harrows come through, it’s a traditional five-bar heavy harrow, it comes through and mixes up the rest of the ground,” Hoffman said.

The 20-inch coulters face forward, have eight waves and are mounted on a service-free hub. The four-bolt hub is mounted on a half-inch by four-inch wide, 6150 steel spring.

The main frame is made from 12-inch by 12 3/8-inch thick tubing.

“You need the weight to get the disks into the ground. If you run into very hard ground, it (the main frame tubing) can be filled with water. It takes about 280 gallons of water, so you can add about 2,800 pounds per wing. That’s roughly 28 pounds per opener of additional force to get into the ground and break it up,” Hoffman said.

The five-bar heavy harrow on the back are 5/8th-inch by 26-inch long tines with wear tips, and are hydraulically adjustable from the tractor cab.

“It’s mounted with parallel arms for ground-following capabilities. It also has an adjustable spring so you can adjust the down pressure on the tine angles. The tine angles are able to go from 35 to 90 degrees so you can stand the harrows straight up if you like for more aggressive action,” Hoffman said.

The coulters are also connected to the frame with a parallel link system, and users can raise the disks all the way up and use the harrows only.

The DHX-600 has a single point depth control for the coulters.

“The depth control for the coulters is a sliding poppet valve, so you just slide it and you can adjust the depth of the coulters. Once you find your sweet spot, just lock it down and you’re good to go,” Hoffman said.

Horsepower requirements for the 60-foot disk harrow depends on field conditions, coulter depth and the angle the harrows are set.

“The tractor horsepower can range a lot. If you have eight horsepower a foot, which equals out to 480 h.p., you won’t be disappointed. But we’ve also had people tow this with tractors with 325 h.p. and they were happy with it,” Hoffman said.

The disk harrow folds up like a traditional harrow, backwards, and is 15.25 feet wide, 14.5 high and 25 long in transport position.

“But something unique to it is that we got rid of the traditional cables that hold the wing lock. We’ve gone with a hydraulic cylinder. So, no more cable stretching or catching on things or the wing opening. This cylinder gets rid of all of that. We also put in an additional safety pin that goes in place to make sure that this (wing) never opens up during field operation,” Hoffman said.

He said Schulte is looking into incorporating a broadcast applicator with the machine.

“So … you could perhaps seed canola with the disk, where you could get that shallow seeding depth that you want. Or you could spread fertilizer or herbicide and mix it in really well with the disks and the harrows,” Hoffman said.

Retail price for the unit is about $170,000.

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