Media Release 23/03/01
NASA inspired Kiwi farmer's shearing shed invention
Who would have thought a device, whose conception came from NASA, would start out resembling a plastic rubbish bin,
herald an important breakthrough for farmers and take 15 years to refine.
It has taken dedication, as well as the input of numerous organisations and people, to get the Hanna Pasture Meter to a
stage where it could soon be practical and financially viable for use by farmers.
Pasture meters are used by farmers to estimate their pasture resource when planning the grazing rotation of their stock.
A major problem with current meters is that they measure total pasture matter, including the dead grass that stock don't
eat. This prompted Tokoroa farmer Mac Hanna to design a meter that measured green pasture only. That was 15 years ago.
Mr Hanna had read that NASA used satellites to estimate live vegetation cover on earth. He rang NASA, obtained technical
details and modelled their approach using a black plastic rubbish bin. The prototype was built in his shearing shed.
HortResearch first became involved when Mr Hanna visited Peter Schaare in 1985 at the Ruakura Research Centre. Mr Hanna
complained that the pencil and notebook he used for collating information, was ineffective in the rain. Dr Schaare soon
fixed that by updating the meter's electronics and by installing a small computer for data logging.
The latest meter has been tested this summer. It has been refined over the last two years in a joint venture between Mr
Hanna, the University of Waikato, AgResearch and HortResearch. Mr Hanna is still involved even though he is now retired
and lives in Australia.
Dr Schaare said the latest model is a step above earlier ones because it functions using Light Emitting Diodes (LEDs).
He said the beauty of LEDs is that they can be used in a device that will be affordable and practical for all farmers.
"Once we have proved that LEDs are an effective measure, it is a small step to making a light- weight, robust pasture
meter which only measures live vegetation."
One possibility for the final version of the Hanna Pasture Meter is to combine it with a Global Positioning System and
mount it on a four-wheel farm bike. This would mean the meter could run independently and record data while the farmer
travelled the farm. Words 382
For more information contact: Dr Peter Schaare HortResearch
Ruakura Tel: 07 858 4760 Fax: 07 858 4705
Email: pschaare@hortresearch.co.nz
Caleb Hulme-Moir HortResearch Palmerston North Tel: 06 3517000 ext 7728 Fax: 06 351 7038 Email:
chulme-moir@hortresearch.co.nz