7 minute read
Working the Land
Brent Lilley headed to New Zealand’s Whakatane region to check out the Kuhn Optimer 4003 in this 2016 review
Kuhn Optimer 4003
Working width
4m
Transport width Number of discs
3m 32
Diameter of discs Power requirement Weight Transport Wheels
510mm 200hp 3,390kg 400/55 x 22.5
While the weather has a big part to play in any cropping situation, getting the ground worked up and then planted in a timely and efficient manner also has a significant effect on the outcome. Nigel Timbs knows this all too well. Starting out as a fencing contractor in New Zealand’s Bay of Plenty region, today he also carries out contract maize grain growing where he crops around 150 hectares of ground every year. With a continual rotation of maize grown on fertile river flats, there is a large amount of stubble and crop residue that needs to be incorporated back into the soil with a disc harrow after harvest, and he bought a Kuhn Optimer to do the job.
DISCS
The Kuhn Optimer 4003 is a compact trailing disc harrow that has been designed specifically for cultivating at speed to a shallow depth and to incorporate residues. To do this, it firstly uses large 510mm-diameter scalloped discs set at aggressive opposing angles to cut into the soil. The 32 discs are arranged in two gangs across the 4m width of the machine and run on slim individual carrier arms that give plenty of clearance for soil and stubble movement through the machine. Each disc is mounted to the carrier arm on an individual cast hub that houses a completely sealed bearing unit, which is greased for life, saving time and lowering the maintenance requirements. Fairly common, but still good to see in this machine, is that the carrier arms are mounted with rubber blocks sandwiched in the clamps on the frame. This allows individual movement to prevent damage if a solid object is struck. The overall working depth of the discs of the machine can be varied anywhere between 30mm and 100mm. This is easily changed without tools, using a screw adjustment stopper that incorporates a clever scale and a simple pin-andhole setup on the rear roller.
TINES
Set behind the discs is a row of light and adjustable straight spring tines that further help to level and bury residues. Although they don’t look like much, it was surprising to see how effective they were without blocking up in the large amounts of maize trash. The working height is adjustable, and the tines can be lifted clear of the ground if not required. It uses a simple pin-andhole setup, and the design cleverly incorporates a handle with enough leverage to make it easy to lift the tines up and down when adjusting them with little effort.
CONSTRUCTION
All components on the machine are carried on a well-built, robust yet compact mainframe, with large 400/55-22.5 flotation tyres that are used to lift the machine out of the ground when turning on the headlands or for transport. To keep the overall transport width under 3m, there are outer wings on either side that can be hydraulically folded and carried vertically. Cleverly, when the outer wings are in the working position, there is a choice on the folding rams between a fixed position (to keep the machine level and rigid), and a slotted hole (which allows the wings to move up and down follow the ground contours). It seems a good idea to have the choice.
Looking for a disc cultivator?
Search for ‘disc cultivator’ on
TradeFarmMachinery.com.au
or type the TA or DIY code shown here into the keyword search field
$35,200 TA1063552
2
4 3
5
Up at the front of the machine is a solid two-point hitch that allows movement in all directions. This hitch also allows for tighter headland turns and means the machine can easily be levelled on the three-point linkage for a level finish. A telescopic drawbar would be an improvement to the machine, although not a problem in Timbs’ situation. If you are running wide duals, the short drawbar will limit the turning ability. A hose needle keeps hoses and cables out of harm’s way, and a well-placed stand makes it easy to unhitch. Although overall the machine is well built and tidy, a passing comment on the day was that already after only six months, the paint work had started to fade and show some blemishes.
REAR ROLLER
Like most similar machines, the Kuhn Optimer offers a range of rear rollers to suit the intended usage. There is the T-Ring roller, which is a wide-spaced, open press ring roller; the T-Liner, which is a deep ring steel drum roller; and the Packliner, which was fitted to Timbs’ machine. The latter is a large, 600mm diameter deep ring roller, which is coated with a hard rubber that enables it to work well in damp conditions without soil sticking to it. There are still scrapers fitted to keep it clean as well. It was reasonably damp the day I was there, and the roller was handling it well. It provides excellent consolidation across the width, and further breaks down clods in the soil to leave a firm level surface.
ON THE JOB
Interestingly, Kuhn recommends around 200hp (149kW) on the front of this 4m unit to achieve good forward speed. However, on the day, a John Deere 7530 on the front with 180hp (134kW) on tap seemed to be managing a respectable forward speed of around 12–14km/h and achieving a good finish – though this was on dead flat ground. Having covered close to 150 hectares, Timbs says he is pleased with the results so far. He is pulling it with the same tractor and managing similar forward speeds – yet covering an extra metre of ground with every pass, lowering running costs, and improving work rates. It was also noted that the material flows through the machine better, leading to fewer blockages, and residue breaks down noticeably faster than in the past.
THE BOTTOM LINE
Machines that combine shallow cultivation and incorporation of crop stubbles with reasonably fast forward speeds and, therefore, high output work rates have gained huge popularity in Europe, and are appearing more in Australasia. I have been lucky enough to see roughly five examples from different manufacturers over the last six months, and all had good points in their own right. In my opinion, the Kuhn Optimer is a simple yet reliable machine that is easy to set up and simple to adjust. It achieved good results in our test, and I was impressed to see this 4m model working well behind a 180hp tractor. I guess, for me, the bottom line is that the owner is incredibly pleased and impressed with the results from the machine.
1. The Kuhn Optimer 4003 compact trailing disc harrow 2. Stockland Agri owner Nigel Timbs 3. The Kuhn Optimer is a simple yet reliable machine 4. A solid two-point linkage hitch allows movement in all directions and to be levelled with the height of the hitch 5. The row of finger tines in front of the roller is easily adjusted by a decent handle along with a pin-and-hole setup
Pluses
Large scalloped 510mm diameter discs Individual carrier arms with rubber blocks allow movement away from solid objects 4m working width with a 3m transport width Outer wings can be on a fixed level or float to follow contours Large flotation tyres minimise compaction and provide stable transport
Minuses
Telescopic drawbar would be an improvement for those running duals Paintwork showing signs of fading
