Choosing disc cultivators for lower powered tractors

A small tractor towing the right disc cultivator, such as the Kuhn Optimer, which was created especially for smaller machinery, can create as good as – or better - seedbeds than many of its bigger ‘siblings’, according to Northumberland-based grower Michael Thompson. This is because he found it was easier to put the drill through the seedbeds.

The cultivator, purchased last year to replace a power harrow, has not only been key to creating a good seedbed, but also allowed drilling operations to start more quickly than with the power harrow, says Mr Thompson. This could be connected with not only the quality of the discs, but also the overall weight on the land.

“We farm on medium to medium-heavy soils, and no two fields on the farm are the same. Last year, the wet autumn weather left the ground sodden, so some would say conditions were not the best for testing new equipment, but others would say it put it through its paces,” explains Mr Thompson, who farms 140ha with his father.

“We found that because the quality of the seedbed was better, we actually used less fuel drilling than we had been when following the power harrow. This is in addition to the reduced fuel costs of using the combination of the tractor and the Kuhn cultivator.”

Assessing suitability of new machinery to work with existing kit is crucial and before choosing a new disc cultivator, farmers need to carefully assess their available horsepower, according to Will Waterer, product specialist for non-inversion establishment at Kuhn Farm Machinery.

Some of the main factors determining a customer’s decision when looking at this type of machine include, not only horsepower requirement, but also factors such as weight, and if it is suitable to go behind a smaller tractor.

With modern precision farming methods, versatility also plays a role as growers need to know whether it will work a range of soil types to varying depths. Performance is also key, he says, as growers frequently want to know how effectively it will bury trash, at what forward operating speed, ha/hour, says Mr Waterer.

“Customers are also keen to ensure they are purchasing a machine with a good build quality. As an example, Kuhn’s smaller machines are manufactured to the same standards and in the same factory/foundry as its larger machines.

“This means they are just as robust as their larger scale ‘siblings’.” He notes that Kuhn Farm Machinery recently launched two mounted versions of its Optimer stubble cultivator for use with lower power tractors: available in working widths of 3 or 4 metres, the new Optimer XL 100-series features machines with two rows of independent discs followed by a roller bar which can be equipped with a variety of Kuhn press wheels, he explains.

Both versions use large diameter (620mm) notched discs made of 6mm thick steel which are capable of working at depths from 5 to 15cm: working depth can be adjusted either manually as standard or hydraulically as an option. The large diameter of the discs makes them able to incorporate high volumes of trash and crop residue easily and efficiently.

Each disc is mounted on four elastomer blocks which enable them to move independently over obstacles, thereby maintaining an even working depth across the machine’s full width, even when working in very stony conditions. Adjustable soil retaining discs which can be angled 14deg. to the front or 14deg. rearwards, and by up to 12deg. vertically, prevent soil being thrown out of the cultivated strip and maintain level and consistent seedbed preparation, adds Mr Waterer. The second row of discs is followed by a roller bar which can be equipped with a choice of tube or ring rollers. All discs and rollers are mounted on sealed-for-life, no-maintenance bearings.

“The compact design of the Optimer XL 300 and Optimer XL 400 makes both machines compatible for use with smaller tractors: the 3m version is suitable for 105-165hp tractors while the 4m version requires 140-220hp.”