Kuhn Farm Machinery has 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 machines feature two rows of independent discs followed by a roller bar which can be equipped with a variety of Kuhn press wheels.
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 14o to the front or 14o rearwards, and by up to 12o vertically, prevent soil being thrown out of the cultivated strip and maintain level and consistent seedbed preparation.
The second row of discs is followed by a roller bar which can be equipped with a choice of tube or ring rollers (see table below for individual roller specifications). 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.
OPTIMER XL specifications
| OPTIMER XL 300 | OPTIMER XL 400 | |
| Working width (m) | 3 | 4 |
| Transport width (m) | 3 | 4 |
| Number of discs | 24 | 32 |
| Disc diameter (mm) | 620 | 620 |
| Disc thickness (mm) | 6 | 6 |
| Working depth (cm) | 5-15 | 5-15 |
| Minimum tractor power (kW/hp) | 77/105 | 103/140 |
| Maximum tractor power (kW/hp) | 123/165 | 164/220 |
| Hitch attachment | 2, 3N, 3 | 3N, 3 |
| Weight with HD-Liner roller (kg) | 2,248 | 2,888 |
| Folding harrow | Optional | Optional |
| Starting price (with V-Liner) roller | £19,168 | £26,184 |
| Hydraulic depth adjustment | £453 | £777 |
Roller specifications
| Tube | T-Ring | T-Liner | V-Liner | HD-Liner | |
| Pressure (kg/m) | 75 | 130 | 140 | 145 | 180 |
| Diameter (mm) | 550 | 600 | 600 | 600 | 600 |
| Soil type | Light/medium | Medium | Medium/heavy (with stones) | Medium/heavy | Medium/heavy
(deep compaction) |
