Sowing and field preparation

 

Soil type and field selection

Fields selected for growing lucerne should meet the following requirements:

 

  • possibility of deep rooting; no disturbance in the subsoil
  • well drained
  • pH-KCl on sandy soils: minimum 5,5
  • pH-KCl on clay soils: minimum 6,0
  • no lucerne grown on the field in the last 4 years
  • low weed pressure

 

Soil quality is the cornerstone of a successful lucerne production. Especially on organic, wet soils it can be hard grow lucerne. Therefor fields selection should be done carefully before planting.

 

Lucerne performs better after a cereal or maize crops than after grasses. The reason for that is the high nitrogen release from an old grass sward inhibits Rhizobial activity. After sugar beets, potatoes and oil-seed rape, attention should be paid to an increased risk of stem rot disease (Sclerotonia) or nematodes.

Field preparation

Fertilization and liming should be done before seedbed preparation. Apply fertilizer and lime according to soil analyses and preceding crops. Find out more about that here (link).

 

Lucerne is grateful for soils with good soil structure. Compressed soils need to be loosened first. After that, seedbed preparation can start. For a perfect seedbed, the top soil should be flat and fine. Lucerne seeds are small. Therefor soil preparations should be similar to those for sugar beets.

Sowing period

For the best germination and establishment, lucerne should be sown into soils which are warmed up already (soil temperature >10 °C). Depending on the area and conditions, sowing usually takes place between mid-March and end of April in spring, or in August as second option. In colder areas, sowing should be completed before half August to prevent winter damage in the first year.

 

After sowing in springtime, up to two cuts can be harvested in the sowing year. If sowing in August, look out for snail damage (particularly after winter wheat).

Seed rate

The general seed rate for Yellow Jacket lucerne seeds is 25 kg per hectare. This is to ensure an establishment of at least 300 plants per m2 after germination. Higher seed rates (30 kg/ha) are recommended under difficult sowing conditions, or if mechanical weed control is planned.

Row distance

If weed problems are expected, a narrow row distance (<10 cm) should be applied. Using a sowing machine with broadcasting coulters will give better spreading of the plants. This will give weeds less of a chance.

 

At low expected weed pressure, larger row distances (up to 22 cm) can be used to apply mechanical

weed control (harrowing machine).

Inoculating with Rhizobia

With the aid of the Rhizobium bacteria in the root nodules, the lucerne plant will fix nitrogen from the air. Therefore, additional nitrogen fertilization is usually not necessary.

 

However, Rhizobia are not freely available in all soils, so it may be necessary to add inoculants during sowing. Even better, use coated seeds with a Rhizobia inoculant. Barenbrug supplies their seed with Yellow Jacket coating to ensure perfect establishment and nitrogen fixation during growth. The use of inoculated seeds is generally recommended.

Post-emergence management

Seed-soil contact is essential for fast germination. If a sowing machine without compacter/roller is used, extra rolling is advised to compact the upper soil level. Especially if no rain is foreseen in the days after sowing.

 

After establishment, weeds should be controlled in an early stage. Annual weeds can be removed by an early cut (topping) – cut as soon as possible, but cut the weeds only.

Mechanical control, with a harrowing/weeding machine, is also possible once the lucerne is well established. Especially chickweed and shepherd’s pure can be controlled by these measurements.

 

It is possible to apply herbicides, but lucerne is susceptible to many contact herbicides. Therefore, care should be taken and contacting an expert is recommended. It is known that bentazone and MCPA can be used in alfalfa, if the right dosage and application is used (not allowed in each country, contact your supplier).

Click here for more information about climate zones in Europe and the Mediterranean  Click here for more information about climate zones in Europe and the Mediterranean

 

Click here for more information about climate zones in Europe and the Mediterranean

Depending on the climate zones, Barenbrug offers various Lucerne products. Every product has its own features suitable for different conditions.

 

Click here for more information about Lucerne