Chain-linked disc harrows offer speedy stubble management

Chain-linked disc cultivators have yet to take off in the UK, but their simplicity, moderate power requirement and ability to incorporate stubbles at high speeds could change that.

The versatility of these tools is also attracting attention, as they can be used to encourage weed seed germination, mulch maize stalks to hamper over-wintering pests, and destroy catch- and cover crops prior to drilling.

Some also have the option of adding seeder units, creating a speedy one-pass system for re-establishing this type of crop.

See also: 10 single-pass cultivator options for heavy land

The concept was conceived by South Australian farmers Shane and Peter Kelly, whose Diamond Harrow has been sold all over the world in myriad widths and disc configurations.

Many Kelly machines are working across Europe and there are a few on UK farms, too.

Plus, its success has prompted a few rival manufacturers to get in on the game, two of which are Danish firm Dalbo and German maker Fliegl.

Each of these makers has subtle variations in their design, but the basic format is the same.

This consists of a hydraulic-folding frame in a cross-formation, to which four sets of chain-linked discs are slung across each corner.

Just two bearings are required on each gang of discs, one at either end, meaning they turn as a complete unit.

However, the fact that the discs are linked by chain-style couplings means they can flex to follow ground contours.

Operators can adjust how aggressively the discs work by altering the tension on the chains, adding weights, or switching to a different style of disc.

Most models are designed to work at depths of 20-50mm and move all soil across the width of the machine. Speeds of up to 18kph are also possible and they tend to require tractor power of about 25hp/m.

This puts them somewhere between a straw rake and a conventional set of discs, offering more soil movement than the former and faster working speeds than the latter.

Dalbo is presently the only option officially on sale in the UK, but Fliegl dealers should be able to source machines and Kelly Tillage is on the hunt for a UK importer after ending its deal with Weaving Machinery in 2018.

Dalbo Powerchain 800

© Dalbo

Danish cultivation specialist Dalbo introduced its Powerchain 800 disc cultivator earlier this year and has several demonstrator models doing the rounds on stubble incorporation.

At present, the 8m machine is the only size offered by the firm, but both smaller and larger versions are on the cards.

Central to the design is a hydraulic folding chassis that shrinks to 3m for transport and incorporates a platform for a cover-crop seeder – Dalbo offers 300-500-litre Einbock units with distribution plates positioned between the front and rear discs, but buyers can fit a make of their choice.

There are also support wheels on either wing to help carry the weight of the discs.

Rather than making its own discs, Dalbo has sourced them from Australian firm Bute. Each chain holds 31-35 units, which are set at a 40deg angle of attack to give a full cut across the width of the machine.

Chain tension is hydraulically adjustable to suit the conditions and up to three 2.4kg weights can be added to each disc to adjust how deeply it works. Its typical working range is 20-50mm deep.

The Powerchain 800 weighs about 6t and is designed to work with a 180hp tractor. List price is £57,000.

Fliegl KSE680

© Fliegl

Fliegl introduced its KSE680 disc chain harrow in 2020, which has a working width of 6.8m and four gangs of 350mm chain-linked discs.

Its layout features a simple cross-shaped frame that has hydraulically suspended wings and has been built to handle working speeds of 10-18kph.

This means it can cover up to 12ha/hr in a wide range of applications, from stubble and cover-crop processing to seed-bed preparation and slurry incorporation.

Overall weight of the rig is 5.7t, with the discs exerting 120-148kg/m of pressure, depending on the setup.

Operators can adjust how aggressively it works thanks to hydraulic control of chain tension and working height.

Each chain-linked disc segment weighs 2.7kg and they are hardened to increase their durability. However, if a unit does get damaged, it’s relatively easy to remove and replace.

Optional extras include a second set of weights, a control panel and hydraulic brakes. 

Kelly Diamond Harrow

© Kelly

The original chain-linked Diamond Harrow from Kelly Tillage was designed for huge Australian farms, but the firm offers more compact versions to suit European conditions.

These can be fitted with different types of discs, including heavy-duty 360mm CL2s spaced at 215mm to deal with large amounts of trash or the more versatile CL1s, which are lighter weight, have a 323mm diameter and are mounted at 163mm spacings.

The company has also launched a new K4 disc that is similar in size and weight to the CL1 but has a shallower concave (25deg) for better weed control across a wider range of soils.

Customers get the option of a spiked disc or prickle chain, too, which carries 132 spikes/m.

Variants include 6m and 9m units that fold to 2.4m wide and a 12m version that comes in a shade under 3m in transport mode.

Power requirements are 120hp for the 6m, 150hp for the 9m, and more than 200hp for the biggest model. Maximum working speed is just over 12kph for a quick one-pass mix.

At present there is no UK importer, so buyers will have to contact the firm directly to arrange a purchase.