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6. Full occupation of a paddock by mallee
competition.
might be represented by 200-300
mallee/ha, either on a uniform spacing of
approximately7x7m, or closely spaced
belts to facilitate harvesting efficiency.
6. Harvest efficiency is maximised when the
concentration of biomass per metre of row is
maximised and distance between belts is
minimised.
Competition between mallees for soil
moisture precludes higher density
planting if long-term biomass production
from many cycles of harvesting is a
principal objective. These higher density
block plantings would virtually exclude
annual cropping from the paddock but
7. Expansion in the sugar industry has
generally been driven at a local mill area scale
in response to market forces. Future
expansion in mallee production will be driven
by the market for biomass and farming
systems and layouts will need to adapt to the
economics of this supply arrangement.
would allow some grazing and stock
shelter. This strategy may be suitable for
soils not suited to annual cereal cropping
(e.g. deep yellow acid sands).
8. Sophisticated information and data
collection systems have developed in the
sugar industry to manage supply areas and
volumes. These systems are could be readily
customised for biomass industries.
9. Where mallee planting is not intended for
biomass removal, consideration will need to
be given to protocols for carbon credits under
the carbon farming initiative.
10. Mallee planting provides vegetative
biodiversity in a wheat monoculture and the
collateral benefits of this biodiversity and
associated environmental dividend needs to
be quantified.
11. A resource inventory of the existing mallee
in WA is essential for development of
commercial operations.
Sugar Industry Mallee Woody Crop Differences/Contrasts Key Issues and Recommendations
Harvesting Transport and Storage Systems
1. Sugar plantations typically cover
large continuous blocks of typically
greater than 20ha allowing high
harvester utilization and efficiencies
2. Sugar industry has collected a lot of
information related to harvesting best
practice and machine performance.
3. Sugarcane presents a fairly uniform
crop to be managed by a harvester.
4. Material handling characteristics of
sugarcane has been well researched
and documented and machinery
designed to provide optimum pouring
1. Mallee typically planted in double rows
separated by 50m-150m of wheat and
other crops.
2. There is very little published data
available relevant to the mallee harvesting
systems
3. Mallee biomass has a variable
characteristic and does not flow very well.
Tipping and bridging can be a problem
and bulk density can be low. Control of
chip quality, leaf and twig material is
difficult in the harvester, all of which
affect material flow, angle of repose,
1. High shift-average sugarcane harvester
throughput of typically 60 to 90 tonne/hr
are achievable versus likely 20-40 tonne/hr
for mallee. Low pour rates result in high
costs of harvesting.
2. Sugarcane harvester field efficiencies are
typically 50% which would be expected to
be lower than for mallee 70-80% given the
long row lengths, low harvesting speeds,
and reduced number of times the harvester
needs to turn per hour.
3. Good quality data on mallee harvester
performance is being collected which will
1. Mallee harvesting costs are expected to be 3
times that for sugarcane. With increased
production volumes and higher delivery rates
this could drop to twice current sugarcane
harvesting costs. New field layouts and
increased harvester performance need to be
considered to reduce these costs.
2. Current trials provide opportunities to
optimise harvest performance and collect
appropriate information on fuel consumption,
vehicle utilisation, harvester location, power
and pressure and material flow, bulk density
etc. This should include matching the power in
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