This month Mark Fouhy checked out a cultivation combo made up of a Dolomit 9 pre ripper, coupled to a three-metre Zirkon 8 power harrow, produced by Lemken.
At the recent Waikato Kubota drive day, Lemken was the machinery of choice putting the latest Kubota tractors through their paces. European-based Lemken machinery is imported and available through CB Norwood. What caught my eye was the power harrow set up, with the pre ripper mounted in front making a great job of preparing ex-maize ground for going back into pasture. This combo was a three-metre Dolomit 9 ripper and a Zirkon three-metre power harrow.
Test
A recently harvested maize paddock just out of Matamata was the test site for the Lemken power harrow/ripper combination. With the latest 150hp Kubota M7 series hooked on, conditions for ground work were excellent. The maize stubble had been mulched, removing the bulk of the trash, but build up and blockages through the day were not an issue for the Lemken combo.
The build and innovative design features are standout points of the Lemken gear I have seen. Operation is pretty straightforward – select 1000 PTO speed. The only downside of the winged Dolomit ripper in front of the power harrow is that it is a little harder to leave the headlands tidy without lifting the ripper legs.
Build quality
Always important in a machine which is to spend its life working a variety of soils is how well it is built, and whether it can handle the tasks while doing a good job. A top and bottom trough system makes up the main profile on the Zirkon power harrow. This is done for strength, with the housings for the 12 rotors welded on in place and drilled out to ensure accuracy and help with bearing reliability over the machine’s lifetime.
Using this system also means there are no bolts holding bearing casings on the bottom side for stubble or trash to get caught on. Adjustment of the triangle levelling bar can be done with a spanner which is kept in the toolbox built into the head stock. Like most power harrows, there is still a chance of rocks making their way up and trying to jam between rotors.
Tines
A bed of 12 tines covers the three-metre working width of the Zirkon 8 model. Lemken power harrows use a timed sequence across the bed to prevent soil being bulldozed which also produces a tidy finish. This also requires less horsepower to operate, is quieter, and easier on the tractor and power harrow gearboxes. Although it may not look like much, a few degrees can make a lot of difference, particularly in power harrow tines.
The Lemken tines slight bend allows them more to cut the stubbly trash into the soil as opposed to having it keep building up the tines to wrap around the rotors, needing to clean out at the end of the day. As a three-metre machine with a 170hp-rated gearbox, I would say the Zirkon 8 is aimed at the farmer market as opposed to contractors, which is why I would guess the 300mm bolt on tines are standard, with 320mm quick change tines optional, where longer quick change tines are standard on Zirkon 12 four- to six-metre machines.
Roller options
CB Norwood farm machinery sales manager Paul Southgate says most of the Lemken power harrows it sells have packer rollers fitted, as well as scrapers, to handle dry or wet conditions. Lemken makes a variety of other options like bar rollers which can be fitted if required. What I did like about the roller set-up on the Zirkon unit was the fact the roller carriage was attached to the levelling bar, which did away with the need for checking and adjusting.
The onboard toolbox built into the headstock contains a double-ended 24/30mm spanner which will fit all the bolts on the Lemken machine. Another feature of the levelling bar is its triangle shape which helps force soil under, rather than being a flat surface which can tend to bulldoze.
Dolomit 9
I am a fan of ripping soil and removing compaction and allowing air, water and roots to more freely move through the soil profile. You don’t always need to deep rip which is quite an expensive job. Coupling the Dolomit 9 ripper pre-loosener to the Zirkon power harrow gives the ability to complete cultivation in a single pass operation, saving time and fuel. With the mechanical action of ripping the soil first, effort to drive the power harrow is decreased, reducing total fuel required if you were to complete another pass with a primary tillage implement.
The four ripper legs of the Dolomit can be independently adjusted while attached to the power harrow, to work to deeper or lesser depths, depending on soil types, pans and compaction. The 60cm-wide, one-piece wing design covers the entire width of the three-metre power harrow. The hardened tips rip through the soil approximately 50mm deeper than the wings, preventing a pan forming, shattering the soil to over the wings and up into the following power harrow tines.
Lemken has kept the length of the Dolomit down to 500m. Coupling close behind the tractor decreases the weight hanging out further when used in conjunction with a power harrow.
The Dolomit 9 model weighs in at 430kg, while the Lemken Zirkon 8 power harrow is a lot heavier at 785kg. Horsepower requirement for the ripper alone is similar to a three-meter power harrow – 80 to 170. Operating in tandem obviously will require more horsepower, with weight to go with it also crucial to drag the four anchors through the ground. Paul Southgate, farm machinery sales manager for CB Norwoods in the upper North Island had that sorted, with the new Kubota 150hp M7 series hooked on with a decent weight block on the front linkage.
Although designed to work in conjunction with Lemken power harrows, the Dolomit ripper has a variety of mountings to suit other brands. It also comes with an extra length of PTO shaft as the original will be too short to reach the extra 500mm.
The verdict
If you hadn’t guessed by now, I am a fan of combination machines which make jobs faster and more efficient. The Dolomit 9 and Zirkon 8 together tick the boxes in this regard. Other agronomic benefits include not repacking the loosened soil back down with the second tractor pass, and the power harrow being able to work the soil evenly to prepare the ground for sowing.
From the test machine, the addition of a seeder unit to make into a true one-pass machine is a pretty simple addition. The quality and build of the Lemken product really impressed me with some of the simple design features making a big difference to performance and function of what is otherwise a pretty normal power harrow.
Pros
- Combination machine, capable of completing more jobs in one pass, with air seeder
- Quality well-built machine with innovative features
- Levelling board and rear roller mounted together, saving time on adjusting
Cons
- Quick change tines as an option, bolt-on standard
- Width of wings may be an issue in poorer soil conditions
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