When looking at a new tractor, there is always great advantage in having it working rather than driving around a test track, and Kehoe Bros Machinery of Co. Wexford had arranged for a set of 6m Pottinger discs to be attached to the rear of its Fendt 620 Vario demo tractor when Agriland went to try it.
The Pottinger Terradisc 6001 is not a newly developed machine – it has been with us for a couple of years now – but it does represent the sort of work that a mid-range tractor will be tasked with.
At 209hp, the Fendt easily met the 190hp minimum power requirement recommended by Pottinger.
Discs are often a ‘maid of all work’ and have as many uses as there are farms using them, so versatility and the ability to set them up easily to suit the conditions and job in hand are paramount.
Working depth
On the day, the disc set was being used to produce a fine tilth ahead of a maize drill and was operating at a depth of around 2in (5cm) with 6in (15cm) being possible with the 58cm diameter discs.
Sunshine and a drying wind meant that the combination was not challenged to any extent, but it did allow the virtues of the Terradisc to be demonstrated, chief among which are its operational simplicity and weight distribution in work.
The working depth is altered simply by lifting it out of work and inserting or removing steel collars sitting on the end of the lifting ram – an easy job and very effective for discs on a frame supported by the tractor at the front and the roller at the rear.
There is also a row of paddles at the front, which are swung into work hydraulically, a system that also allows an infinite number of depth settings.
Pottinger uses the weight
Yet the mayor feature of the Terradisc range is the way in which the road wheels fold up and come to rest above the centre of the frame.
This ensures that their weight is evenly balanced fore and aft without weight transfer from the rear of the tractor, as is the case with other makes when the undercarriage is left in position at the rear of the machine.
When folded up, the weight of the undercarriage is held where it is useful, for instance, encouraging the discs to cut into stubbles without having to add ballast or alter the angle of the discs.
This system also helps stops the discs bouncing out of work and makes for a smoother ride.
There is one feature which Pottinger has moved away from and that is the adjustment of the angle of attack of the discs.
According to Tom Barron, salesperson for Kehoe Bros, this was because this feature was found not to have as great an effect as was previously thought, so the engineers decided on the present standard offset as the best compromise – and nobody appears to have complained.
Cover crops
Fitted to this particular model, was the optional 500L Tegosem fan seeder unit, which is designed to deliver cover crops or other small seeds to the rear of the frame where it can be pressed in by the roller.
The fan seeder is hydraulically driven and, even when the Fendt 620 is working at maximum output, the extra demand on the engine is catered for by the Dynamic Power system, which boosts output in response to demand from the peripherals rather than the power take-off (PTO).
Barron told Agriland he can see a growing adoption of cover crops as farmers get to realise the benefit to the soil they bring.
He highlighted turnips as being of great interest in the area, as the crop’s deep roots break through the soil layers and improve the structure.
