Australia
October 16, 2008
Twin sowing, a new technique for
sowing legume pastures using hard seed undersown with a cereal
or oil seed crop, could substantially reduce costs of pasture
establishment for Australian growers.
Dr Angelo Loi and Brad Nutt of the Department of Agriculture and
Food WA (DAFWA) developed the technique to encourage the
continued use of pasture legumes in mixed farming systems.
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Twin sown yellow serradella trial: Brad Nutt, DAFWA
research officer and co-developer of the twin sowing
technique, views the GRDC supported trial with
Murray Leach at his Corrigin farm. The trial was
twin sown the year before. |
Dr Loi said incorporating a legume
based ley rotation provided many agronomic benefits in a mixed
farming system, but grazing livestock had lost economic value
relative to crop production in low and medium rainfall areas.
The research has been funded by Pastures Australia, which is
supported by the Grains
Research and Development Corporation (GRDC), Australian Wool
Innovation (AWI), Meat and Livestock Australia (MLA), Dairy
Australia and the Rural Industries Research and Development
Corporation (RIRDC).
Pastures Australia Manager, Rory Coffey, said early results
indicated twin sowing might be an effective technique to
introduce hard seeded pasture legumes in a crop-pasture ley
rotation.
“It has the advantage of not requiring a separate sowing
operation and not conflicting with the cropping program in terms
of timing of sowing,” he said.
“It also provides pasture legumes with the opportunity to
utilise the full growing season.
“An essential feature of the twin sowing technique will be
on-farm seed production of the pasture legume because of the
sowing rates required,” Mr Coffey said.
Dr Loi indicated that yellow serradella and hard seeded forms of
French serradella from pods produced on-farm could be undersown
with a cereal or oil seed crop.
“Seeds in these pods are almost 100 per cent hard and little
germination occurs under the crop,” he explained.
“In the summer and autumn following the crop, the hard seed will
break down to form a seed pool that will germinate if conditions
are favourable.
“The serradella will establish as a regenerating pasture from
this pool, which avoids the time and cost of a separate sowing
operation,” Dr Loi said.
A second essential feature of twin sowing is the successful
introduction of rhizobial inoculants with the hard seed.
A partner in the twin sowing project, The Centre for Rhizobium
Studies at Murdoch University, will monitor which rhizobium
delivery system and which rhizobium species best suit the twin
sowing concept.
Dr Loi indicated the twin sowing technique might be useful for
topping up pastures with low legume content due to drought or
prolonged cropping.
The technique’s success, according to Dr Loi, depended on low
seed cost, appropriate hard seed breakdown pattern, effective
rhizobial inoculation and weed management.
He said the technique could be applied to other legume species
with the capacity to produce low cost seed, such as bladder
clover, gland clover and biserrula.
Dr Loi addressed the twin sowing technique at the GRDC sponsored
14th Australian Society of Agronomy Conference in Adelaide.
He indicated that further GRDC supported trials were underway to
determine optimal seeding rates, seed distribution, rhizobial
inoculation techniques and weed control in the regenerating year
of the pasture. |
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