Last season Lemken was showing UK farmers a pre-production example of its big-disc Rubin 12, and we managed to spend time with the 6.0m version to see what all the fuss was about. Key feature is the increased working depth, and probably of equal significance is the interlocking ring packer that encourages better germination of the dreaded blackgrass.
Lemken sees the Rubin 12 as a key machine for the firm in the UK, with its ability to work relatively shallow or, thanks to those big discs, down to a depth of 200mm. Of equal importance is the interlocking ring packer, which due to its weight is not offered on the Rubin 9 or Heliodor compact disc harrows — see profi news, June 2014; the packer’s consolidating effect promotes blackgrass germination, so the weed can be sprayed ahead of drilling.
First unveiled at Agritechnica 2011, full production of the Rubin 12 did not start until this year, and in the intervening years the machine has undergone a number of subtle tweaks. The leg on to which the disc is mounted has been re-jigged to allow greater clearance between the two components and achieve a 20cm working depth in heavy soils with lots of trash. The auto-reset protection system has also been changed from that early showing.
As well as the greater working range, Lemken reckons the compact disc format, compared to more conventional heavy discs, can leave a leveller finish, which is why it has gone to the trouble of developing the Rubin 12. There are two rows of discs, arranged in a symmetrical pattern so the front gang throws the soil out, while the rear gang fires it back in. This layout reduces the crabbing and lateral drag that can be a hindrance to deeper working.
