Scientific name(s)
Medicago sativa
Strengths
- Perennial, year round production
- Deep rooting, extracts water and nutrients from depth, restricts watertable recharge
- Moderate tolerance of soil salinity and sodicity
- Responds quickly to spring and summer rainfall (or irrigation)
- Dual purpose (grazing and hay)
- Highly productive
- High nutritive value
Limitations
- Short-term persistence in some regions (mainly due to disease susceptibility)
- Susceptible to waterlogging
- Needs rotational grazing
- Can cause bloat in cattle
Plant description
Plant: Deep rooted, upright, perennial legume.
Stems: Erect from 40 - 80 cm high at 10% flower.
Leaves: Comprise three smooth, slightly toothed, oval, wedge shaped to pointed leaflets, sometimes with white crescent shaped markings. Leaf veins strong, straight with little branching. Broadly triangular stipules with one or more small teeth occur at the point of leaf attachment to the stem.
Flowers: Pea flowers, mostly purple in colour, and about 8 mm across, borne in clusters up to 4 cm long at the tops of branches.
Pods: 4 - 5 coils in a spiral, spineless with a hard outer surface; produced in clusters; 1 - 5 seeds/pod.
Seeds: Small, green to yellow to light brown in colour; kidney shaped; 440,000 - 500,000 seeds/kg.
Pasture type and use
Medium term perennial (3 - 5 years); year-round production, predominantly in the spring/summer but with varying levels of winter production (winter activity).Used for conservation, particularly hay production; as a 'ley' legume in cropping rotations (often called a 'phase' legume in such systems in southern and Western Australia); and as a medium-term legume in long term grass pastures in the subtropics.
Where it grows
Rainfall
In rain grown stands, 500 - 1200 mm/ann (subtropics); 250 - 800 mm/ann (southern and Western Australia).
Soils
Lucerne requires deep, well-drained soils (sands to moderately heavy clays) with a slightly acid to alkaline pH. It is intolerant of high levels of exchangeable aluminium and even short periods of waterlogging.
Temperature
Optimum temperatures for dry matter production range from 15 - 25ºC in the day and 10 - 20ºC during the night. However, this will vary with the winter activity level of the cultivar.
Establishment
Companion species
Lucerne is often sown as a pure sward. It is very competitive but if sown at a low rate it will grow with species such as early-flowering sub clover/annual medics, phalaris and Mediterranean types of tall fescue to boost winter production. It can be grown with chicory and a range of tropical grasses.
Sowing/planting rates as single species
2 - 12 kg/ha for dryland hay or grazing, depending on annual rainfall. 8 - 20 kg/ha for irrigated hay production. Sow into a finely worked, moist, weed-free seedbed at 1-2 cm; cover with light harrows/weldmesh. On light soils rolling is desirable to improve seed-moisture contact. Direct-drilling can work but failures occur and caution is warranted.
Sowing/planting rates in mixtures
0.25 - 1.0 kg/ha in a grass pasture, depending on the makeup of the legume component of the stand.
Sowing time
Early autumn to early winter; late April is ideal.In southern Australia districts with an 8 month or more growing season, lucerne is best sown between late August & October, ideally on a winter fallow. Late Spring sowings are dictated by wet years.
Inoculation
Seed must be freshly inoculated with Group AL rhizobia and lime coated. Some pre-inoculated processes may be effective but caution is required.
Fertiliser
On marginal fertility soils, responses to magnesium, manganese, zinc, molybdenum, boron and copper can occur. Establishment on acid soils is often made possible following the spreading/incorporating 1-5 t lime/ha. Aluminium toxicity can occur on soils with pH of lower than 5.5 (water) or 4.7 (calcium chloride). Based on soil test, potassium (K), phosphorus (P) and sulphur (S) levels need to be maintained at the following levels:
- K: 0.3 m. equiv/100g;
- P: 25 mg/kg;
- S: 10 mg/kg.
Management
Maintenance fertliser
Maintenance fertiliser needs to be applied regularly in irrigated lucerne where large quantities of nutrient are removed in hay. Based on soil test, potassium, phosphorus and sulphur levels need to be maintained at the levels indicated above.
Grazing/cutting
Timing of grazing or cutting should be matched to the build up of carbohydrate reserves in the plant's roots. Levels in the roots are lowest about 2 weeks after grazing or cutting and reach their maximum at full bloom, somewhere between 4 - 8 weeks after the previous defoliation (dependent on time of year and winter activity level of the cultivar used).Cutting for hay is best done at 10% flower or when the basal shoots are 3 - 5 cm in length.It should be rotationally grazed for long-term persistence, whether grown as a pure stand or in mixed swards. It should be grazed off in 1-2 weeks followed by spelling for 4-8 week - depending on time of year and winter activity level of the cultivar used.
Seed production
Seed production is a specialised activity. Grazing and cutting management and the timing of cessation of grazing and cutting, fertiliser management, irrigation, weed control and the availability of bees for pollination need to be controlled for optimum seed production. There can be substantial differences between cultivars in potential seed production and this can affect the usefulness of a cultivar.Commercial seed production is concentrated in South Australia.
Ability to spread
Low. Lucerne is usually cut or grazed before seed matures. If lucerne seed is dropped or spread by livestock, it rarely establishes effectively owing to soil and soil water constraints. In lucerne producing environments, it may be found on road verges but not in adjacent paddocks subject to grazing.
Weed potential
Low, in keeping with its inability to spread.
Major pests
Red-legged earthmite, spotted alfalfa aphid, bluegreen aphid, pea aphid, lucerne flea, jassids or leafhopper, vegetable jassid, whitefringed weevil, sitona weevil, small lucerne weevil, lucerne crownborers, lucerne leafroller, weed web moth or cotton webspinner, cutworms, wingless grasshoppers, thrips, lucerne seed web moth, native budworm, lucerne seed wasp, mirids, mites, snails.
Major diseases
Seedling disease: Damping off
Leaf and stem diseases: alfalfa mosaic virus, lucerne yellows, bacterial leaf and stem spot, witches broom, common leaf spot, Stemphylium leaf spot, Leptosphaerulina leaf spot or pepper spot, rust, downy mildew, Cercospora leaf spot, Phoma black stem, powdery mildew.
Root and crown diseases: Phytophthora root rot, Colletotrichum crown rot, Rhizoctonia canker (most significant,) violet root rot, Acrocalymma crown and root rot, Stagonospora crown and root rot (sometimes called common root rot), Fusarium wilt, bacterial wilt, Sclerotium blight and Sclerotinia rot.
Herbicide susceptibility
Herbicides can be used to take out grasses or broadleaved weeds selectively, or can be used pre-planting or post-planting to tackle weeds at different stages of crop development.Mature lucerne is difficult to remove with herbicide. Follow agronomist recommendations and check labels for the herbicides that are registered for use in lucerne or to remove lucerne.
Animal production
Feeding value
Lucerne is highly digestible (60 - 75 %), is a good source of crude protein (15 - 25 %), and has high levels of metabolisable (8 - 11 MJ/kg DM).
Palatability
Very palatable
Production potential
Daily live weight gains for beef cattle range between 0.7 kg/head/day from stemmy lucerne to 1.5 kg/head/day from young, leafy regrowth. Live weight gains of 300 - 400 g/head/day are achievable with lambs.
Livestock disorders/toxicity
There are few problems. To avoid cattle bloat, nitrate poisioning and red gut, do not graze immature/lush lucerne, especially with hungry stock (pre-feed with dry roughage).
Cultivars
Cultivars are rated for 'winter activity' from 1 (winter dormant, negligible winter production) to 11 (highly winter active, 20 - 25% of annual production produced in the winter months). This indicates the ability of a cultivar to grow in cold temperatures and days of shorter length. Winter active cultivars (rated 7 - 11) are used for dryland farming systems in southern and Mediterranean Australia to best utilise the winter dominant rainfall, and in the subtropics to fill the winter production and protein gap. Semi winter-dormant cultivars are used more in the cooler regions as long lasting pasture.
| Group | Winter Activity rating (WAR) | Information |
| Winter dormant | 1-3 | Little autumn-winter growth. |
| Winter semi-dormant | 4-5 | Suitable for long-term stands where persistence of the stand is the main priority. Have broad, low crowns. Used as a companion with annual legumes or grasses in long-term pastures. Low winter production. |
| Winter active | 6-7 | Suitable for long-term permanent pasture with long stand life. Growth slows during the winter months, but does not cease. Low crown. |
| Highly winter active | 8-9 | Have high seedling vigour and first year production. Persistent under rotational grazing, but crown is commonly narrow and more exposed to grazing. |
| Very highly winter active | 10-11 | Well suited to short rotations of 2 - 4 years. Very productive but generally have poor persistence; require careful grazing and cutting to maximise persistence. When cultivars are compared over the long term, persistence associated with grazing tolerance generally declines with increasing WAR. Selection by breeders is helping overcome this limitation. |
Further information
AUSTRALIALucerne Australia Australian Fodder Industry Association Australian Herbage Plant cultivars
Lloyd D, English M, Williams R, McDonald W and Auricht, G (2002). Lucerne Pests & Disorders: the Ute Guide (ISBN 0 7345 0157 9):GRDC)
QLDManaging Dryland Lucerne - Grower's Handbook (DPI Victoria)Lucerne production in Queensland (DPI&F)
Bullen, KS, Franzmann, BA, Harris, GA, Irwin, JAG, Lloyd, DL, Lowe, KF, Mills, WD, Ryley, MJ and Thompson, PJM (2002). The Lucerne Management Handbook 4th Edition ed. KS Bullen (ISBN 0 7345 0181 1:Department of Primary Industries, Queensland)
NSWLucerne Medicago sativa (NSW DPI Agnote 269)
VICRansom K, Trapnell L, Clune T, Hirth J, Whale J, Bate N, Naji R (2006) Making Lucerne Pay: Integrating crops and lucerne on mixed farms. ISBN 1 74146 711 X. . VDPI, GRDC.
SAStanley, M, Britton, R and Christinat, R ((2002). Success With Lucerne (ISBN 0 7590 1325 X:PIRSA, South Australia)
WAGrazing sheep and cattle on dryland lucerne (WA Dept of Agric. & Food)
Acknowledgements
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Author and date
D Lloyd and B Johnson
December 2008
Reviewed by Kevin Reed
