Lucerne for Recharge Areas
Note Number: AG0390
Published: February 2003
Lucerne is one of the major weapons being used in the fight against salinity in dryland areas of the Goulburn-Broken River catchment. It is a deep-rooted, perennial plant that can be used in recharge areas to help control deep drainage.
Lucerne is a particularly valuable plant as it has the following advantages:
- Perennial - it lives up to 10 years when managed appropriately
- Legume - it converts atmospheric nitrogen into soil nitrogen
- Drought tolerant - it has a long tap root that allows it to reach moisture deep in the soil
- High water usage - it has lowered water tables in many cases which helps to reduce salinity (for example at Burkes Flat and Marnoo)
Summer activity - it produces 60% of its yield in the December to April period providing valuable out of season feed
- High production - it will yield more than an annual pasture and therefore stocking rates can be increased
- High quality - it is high in protein and nutritional value
It is for these reasons that lucerne is often called the 'King of Fodders'.
Lucerne on recharge areas at Sheep Pen Creek
Lucerne was compared against annual pastures for persistence, productivity and water use on hill country, identified to be a recharge area, at Sheep Pen Creek near Violet Town. The pasture was established in 1987 and was grazed at three stocking rates (5, 8.75 and 12.25 sheep/ha) from 1988. Persistence of lucerne was unaffected by stocking rate as a strict rotation of two weeks on - eight weeks off was adhered to. However, lucerne failed to persist in the mid-slope areas where it was affected by waterlogging.
Sheep grazing the annual pastures required extensive supplementary feeding during summer, especially at high stocking rates, whilst sheep grazing lucerne required virtually no hand feeding, leading to big savings in feed costs.
Production per head was similar between sheep running at 5/ha on annual pasture and those stocked at 12.25/ha on lucerne pasture. Soil water measurements showed that the lucerne dried the soil out more than the annual pasture, which would help to reduce recharge or deep drainage. The experiment demonstrated large stocking rate increases are possible from growing lucerne, without incurring falls in per head production.
Where to sow lucerne
Unfortunately, lucerne cannot be grown on all soil types in the Goulburn-Broken catchment. Lucerne requires a well-drained soil as it will not tolerate waterlogging. Lucerne is also sensitive to soil acidity and associated problems of high aluminium. Aim for a soil pH (CaCl2) of 5.0 and an aluminium level of less than 2ug/g (CaCl2). Incorporation of lime into the soil may rectify a topsoil acidity or aluminium problem. However, where the subsoil is too acidic it is best to look at alternative species such as phalaris or cocksfoot.
The best way to determine the suitability of a soil for lucerne is to get a soil test done, making sure to submit a top soil sample and a sub soil sample to the laboratory.
In the dryland parts of the Goulburn-Broken catchment, lucerne is best suited to the well drained hills of the Sheep Pen Creek area near Violet Town, the Dookie hills, some of the deep soils around Nagambie and the Riverine plains north of the Broken River. In areas like Molyullah, Tatong, Swanpool, Warrenbayne, and Seymour, small areas of deep, well drained soils such as river and creek flats may be able to grow lucerne but lime may need to be applied first.
How to sow lucerne
Lucerne can be sown in the early autumn but early spring is generally better. If lime is needed, then it must be incorporated by cultivation. Lucerne can be direct drilled and can be sown with or without a cover crop. The most important aspects to consider at sowing are depth of sowing (less than10 mm) and insect control, especially red-legged earthmite. As with all legume seeds, lucerne should be inoculated with the appropriate Rhizobium bacteria and lime coated to ensure efficient nitrogen fixation.
Fertiliser should be applied at sowing and 250 kg/ha of super lime and molybdenum (0.025%) is generally sufficient but a more accurate recommendation can be made on the basis of a soil test. Sowing rates for dryland (non-irrigated) stands are 2 to 8 kg/ha depending on rainfall and soil conditions.
Choosing a variety
Choosing a variety can be a confusing task as there are more than 30 varieties available. Selection of a variety should be based on the proposed use (grazing or hay), expected lifespan (3-5 years or 6 years or more) and period of greatest need (summer or winter).
Highly winter active varieties provide best winter grazing and are quick to establish, but they generally have a shorter stand life. Winter active varieties are similar to highly winter active varieties, but they have a higher leaf to stem ratio resulting in slightly better hay quality.
Semi winter dormant varieties have a longer stand life and good hay and grazing quality. Varieties in this group have a similar growth pattern to the old Hunter River variety. Winter dormant varieties are best suited to either irrigation or dryland areas, where no winter feed is required. They are slow to establish but have a long life and excellent hay quality.
Highly winter active
CUF 101, Pioneer 5929, Pioneer L69, Pioneer L90, Rippa, Salado, Sequel, Sceptre, Siriver, Springfield
Aquarius, Aurora, Eureka, Genesis, Hunterfield, Quadrella, Sheffield, Super Seven, Trifecta, WL 414, WL 516, WL 525HQ
Semi winter dormant
Kaituna, Nova, Pioneer L52, Pioneer L55, WL Southern Special
Cimarron, Pioneer L34.HQ, Prime, WL 320
Table 1. A list of currently available varieties, arranged in their dormancy groups, are shown in the table below.
Management of lucerne
Lucerne should be rotationally grazed to optimise stand life. Under set stocking, lucerne will soon disappear. A suitable rotation is grazing for 1 to 3 weeks and spelling for 5 to 8 weeks. Ideally, a 3 or 4 paddock rotation is used to achieve this, but this may require extensive internal fencing and watering points which is not always possible. Alternatively, stock can be moved onto other pastures or crop stubbles on the farm to achieve the rest period for the lucerne paddock. Lucerne should be allowed to flower in the autumn so as to allow it to build a good reserve of carbohydrates going into winter.
For further information contact us.
This note was reprinted from Goulburn Dryland Salinity Program's Resource Kit.
This Informatuion Note was deveolped by Lisa Warn and Allan Semmler, February 2003.