PREPARATION
Paddock selection
- Ensure paddock to be sown is suitable for growing lucerne.
Soil test for correct soil and nutrient status:
-pH (CaCl2 test) 5.0 – 7.5
-pH (water test) 5.8
- 8.2
-aluminium < 15 mg/kg
-water salinity < 2.4 ds/m
-soil salinity <2 ds/m
-sodium <6%
-Ca:Mg >2:1
(Source: Irrigated Lucerne, NSW Ag).
- Check drainage in irrigation bays – well-leveled bays with no hollows; at least 1:800 slope; and able to irrigate and drain within eight hours.
Seedbed preparation
- Prepare well in advance.
- Create a fine, firm seedbed, clean of any weeds.
Weed control
- Remove as many weeds as possible during previous crop or pasture phase.
- Use pre-emergent for wireweed/hogweed, annual ryegrass.
- Consider post-emergent options for grass and broadleaf weeds.
- Early control is critical to provide best possible establishment for new lucerne.
VARIETY SELECTION
- Select the appropriate variety based on your requirements and the agronomic characteristics to suit your situation.
SOWING
Sowing (use same rates for bare or coated seed)
Rates:
- <400 mm rainfall 2-4 kg/ha
- 400 - 600 4-6 kg/ha
- 600 - 750 6-8 kg/ha
- 750 - 900 8-10 kg/ha
- 900+ or irrigation 10-15 kg/ha
Inoculation
- Ensure seed is inoculated with lucerne rhizobium AL, preferably using Superstrike treatment for improved seedling establishment.
- Use Superstrike Plus treatment for red-legged earthmite control.
Autumn sowing
- Under irrigation or dryland where soil temperatures are 15 - 25°C and plants can establish before cold winter temperatures (and frosts).
- Better suited to winter-active and highly winter-active varieties.
Late winter-spring sowing
- Enables plants to establish into increasing soil temperatures and allows good control of winter germinating weeds.
- Plant early enough to ensure topsoil is not drying out whilst seeds are trying to germinate.
- Suited to all dormancies but especially more dormant cultivars.
Moisture
- Sow into good moisture, with good soil friability – not sticky.
Depth
- 10-15 mm – drop or shallow drill, cover with light harrows or mesh and roll to maximise germination.
Insect Control
- Red-legged earthmite should be controlled prior to sowing or treated immediately post-sowing. Preferably use Superstrike Plus treated seed.
Plant Density
- Stands are viable at 12 plants/m2 dryland and 30/m2 irrigated.
- For irrigation, 120 – 130 plants/m2 at establishment.
MAINENANCE
Cutting/grazing
- Allow new lucerne stands to flower prior to first cutting or grazing.
- Lucerne carbohydrate reserves need to be replenished between grazings and cuttings.
- Graze for periods of 7-14 days followed by adequate spelling.
- Allow 28 days (winter-actives) and 35 days (winterdormants) between cutting during growing season.
- Allow lucerne to flower before last cut/grazing of season.
- Spell during winter prior to herbicide applications.
Fertilising
- Based on nutrient removal, lucerne should be fertilised to maintain its nutrient requirements.
- Nutrients removed per tonne as hay:
-Phosphorus 2-3 kg/tonne removed
-Potassium 15-20 kg
-Calcium 13-17 kg
-Sulphur 2-4 kg
- Maintain visual observations of stand health and if unsure take follow-up soil or plant tissue tests to identify problems.
Weed Control
- Usually undertaken in mid/late winter after good germination of weeds.
- Identify weeds correctly and seek advice as to most appropriate herbicide.
- Rotate herbicide groups over time to avoid herbicide resistance problems.
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