Mine Rehabilitation Handbook - Mining and Blasting

In arid areas it may be appropriate to only treat 30-50% of the seed so
that a bank of ungerminated seed remains if follow-up rains (after the
initial germination event) are not forthcoming and there is a high
mortality of seedlings.
Agricultural legume seed should be inoculated with the appropriate
strain of rhizobium bacterium. This is usually done in conjunction with
lime pelleting, which is a simple procedure easily carried out on-site.
Rhizobia inoculum and details of the pelleting procedure are readily
available from seed merchants.
Rhizobia, which form associations with native legumes, seem to be
tolerant of soil disturbance and storage and will often readily infect
native species after rehabilitation. However inoculation may be
necessary if infection doesn’t readily occur after rehabilitation or when
establishing native legumes in overburden, tailings or sub-soil. This will
involve isolating native rhizobia, growing them on suitable media and
attaching them to the seeds. While this is a relatively simple procedure,
specialist guidance will probably be needed.
5.6.5 Seed Storage
• Clean seed to remove as much debris as possible before storage,
failure to do so may result in fungal infection.
• Label seed clearly including species, date collected, location, etc.
• Store seed in dry insect and vermin proof containers and dust with
fungicide and insecticide powder.
• Loss of seed viability during storage is common. Most seed will keep
for several years but some species cannot be stored beyond 1 or 2
months. For most species, storage at 1-4 degrees C in airtight
containers at less than 10% humidity will maintain seed viability.
• Tropical species may be killed at temperatures below 10°C.
• Dormancy in many Australian plant species is affected by changes in
light or temperature conditions and moisture content.
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5.6.6 Seedbed Preparation
Methods used for the preparation of the seedbed will depend on
topography of the site, the proposed landuse, the extent of soil
amelioration and fertiliser use, and the sowing or planting technique
proposed. The objective in creating a seedbed is to place the seed in a
suitable place for germination. Points to consider include:
• Prevent compaction, crusting and subsequent erosion by avoiding
disturbance to soils when wet and sticky or dry and powdery.
• Application of most fertiliser can be carried out during tillage of the
seedbed. Nitrogenous fertilisers tend to dissipate to the atmosphere
and planting should follow immediately after application.
• Timing of seedbed preparation (and sowing) is often critical for
successful establishment of vegetation. In most cases preparation
and sowing should occur prior to the onset of “reliable” rainfall.
• Where the topsoil contains significant quantities of seed of desirable
species, care must be taken not to disturb the soil after these seeds
have started to germinate, as this will cause a substantial reduction
in plant establishment.
• In southern or alpine areas, soil temperatures also need to be
considered. Local agricultural practices may provide a guide to the
optimum period.
• A variety of heavy-duty conventional agricultural equipment can be
used for seedbed preparation. Disk harrows and chisel ploughs are
both able to operate in stony soil conditions.
• Avoid “over preparing” the seedbed. A rough “cloddy” surface
reduces runoff and provides better lodgement and protection for
seeds and seedlings.
• When hand planting of seeds or seedlings is proposed, site
preparation may best be limited to deep ripping or minimal tillage.
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