- pH correction - aim for 6.0 - 6.5pH for optimum levels.
- Correct nutrient deficiencies, P, K, S, Mo and B prior to sowing.
- Do not focus just on topsoil pH, in some areas subsoil soluble aluminium can be an issue.
It restricts root growth and increases fertiliser requirements. Check soluble aluminium levels at 300mm.
- Use crop rotation to remove weeds from paddocks prior to sowing lucerne.
- Lucerne prefers well drained soils. Root disease such as Phytophthora and others will cause severe seedling damage as well as reducing yields and persistency.
- Spring sow from late September to early November. Timing will be dictated by local environment. In some areas late summer sowings are viable.
- Sow between 8 -- 12 kg per hectare of freshly inoculated seed, as lucerne requires specific rhizobia for effective nodulation.
- Ensure insect pests are controlled.
- Prior to final surface working in cultivated situations, incorporate pre-emergence (Trifluralin) herbicide.
- Shallow sow at 5 - 15mm in a fine firm seedbed, or if soil type is suitable you can direct drill.
- Allow at least 50% of the seedlings to flower following establishment before quickly grazing.
Nitrogen is usually non limiting depending on the nitrogen fixing capability of the stand.
In some instances lucerne will respond to artificial N.
- With high producing crops, nutrient removal needs to be constantly monitored with soil and plant tissue tests to determine requirements.
- Some nutrients will be replaced in grazing situations but not under pure cutting regimes. Ready-mixes of lucerne fertilisers are available to supply micro and macro nutrients.
managing established lucerne
- Lucerne, unlike pasture grasses, grows from the tip of the plant stem, not at the base of tillers.
- Lucerne has a crown on top of the root system, producing crown buds from which new stems are produced through the season.
- The ability of these buds to rapidly develop will be aided by good rotation length of grazing or cutting to enable build up of carbohydrate root reserves. This is usually 25 - 40 days depending on the time of year.
- The timing of first grazing in the spring will be determined by root reserves and timing of winter herbicide together with the stem growth of the lucerne.
- If grazing, the spring grazing should be pre- flowering at about 1500kgDM/ha.
- Grazing through summer should be on a rotation of between 4 - 6 weeks.
- The crucial time to allow lucerne to flower is in the autumn, February - April. Allow at least 30 - 50% flower buds to allow the crop to rebuild root reserves.
Ongoing fertiliser requirements will be determined by soil tests, but usually a split application spring and autumn of a PKS based product plus micro nutrients.
Do leaf tissue tests annually to support soil test results.
- Winter herbicide application on established stands is important to maintain high yielding lucerne crops. Do not apply too late in winter as damage to the crown buds can occur.
- Supply salt licks when grazing. As with any high quality feed a period of adjustment when beginning grazing will help with the animal's rumen adjustment. During this adjustment phase graze on lucerne for half the day then move to pasture for the remainder. Continue this for three to five days.
Bloat can be a risk on lucerne (as it is with any high quality feed). To help alleviate this make fibre e.g. barley straw and mineral blocks available. Remember to never put hungry stock onto lucerne as this can increase risk of bloat.
Redgut is another potential animal health disorder when grazing lucerne. It can be caused by the rapid movement of high quality feed through the gut. The highest risk is generally in the early spring or after rain. To help alleviate the risk provide fibre, e.g. hay, during these times.