Drilling lucerne - establishment is key

Published 14 August 15

Drilling lucerne – establishment is key!

A growing global demand for proteins coupled with the introduction of CAP greening regulations, has led to increased interest in home grown proteins, including lucerne. At an AHDB Dairy and British Grassland Society demonstration farm meeting last month, host farmer James Foote, who is in his third year of growing lucerne, shared his secrets for a successful establishment. Dr Debbie McConnell, AHDB Dairy R&D Manager reports for Forage for Knowledge.

Managing 20 hectares and having planted an extra 8ha of lucerne this year, Chynoweth Farm is now well versed in establishing the crop. Wanting to reduce bought in protein costs, James was keen to explore sources of home grown protein. The farm initially experimented with both vetch and a lupins-wheat combination to varying degrees of success, before trying lucerne.

James’s establishment process:

  1. Soil test pre-cultivation and correct pH (target pH 6.5-8.0)
  2. Spray with herbicide, a clean seedbed is essential
  3. Plough
  4. Subsoil to remove any deep compaction
  5. Cultivate to produce a fine firm seedbed similar to that for maize
  6. Drill seed to 1cm depth. Target seed rates = 20-24kg/ha.

“Getting a successful establishment is key,” said James. “The plant is autotoxic, meaning that once plants start to grow, they excrete chemicals called exudates from their roots which stop any new seedlings growing. As a result there is little opportunity to overseed patchy areas making establishment really important.” 

Lucerne establishment

Recently established lucerne at Chynoweth farm

Lucerne is usually known for its drought tolerance and performs better on free-draining sites and soil types. It does not perform well in waterlogged soils as the tap root can rot. On Chynoweth Farm lucerne has followed potato, maize and grass crops. Sub-soil structure is also important due to the deep rooting nature of the crop, roots often go down over 1m in depth. James routinely uses a subsoiler to remove any compaction during the establishment process.

Soil pH is one of the most important success factors for lucerne. Having a high calcium requirement, the plant flourishes in alkali soils, therefore, it is important to aim for a pH between 6.5 and 8.0. James uses sea sand to improve the pH of the soil, this year applying it in between subsoiling and cultivating rather than before the plough. James also stressed the importance of a clean seed bed and correct weed control. Because lucerne is very slow to establish, it is important to make sure competition from weeds is supressed.

When drilling, lucerne requires high seed rates (typically 20-24kg/ha) and should be sown no deeper than 1cm, as the seed is very small. Typically, rows should be 10-12cm apart, with rolling essential to get good seed-soil contact. For pure stands the aim is to achieve 500-800 seeds per square meter at establishment.

Although it may be possible to establish lucerne in some areas later in the season, recent trials at the University of Reading, Harper Adams University and SRUC have shown that spring establishment is a safer alternative. Professor Chris Reynolds from the University of Reading speaking at the event said: “At all three sites of our AHDB Dairy-funded trials, we had much greater success with spring establishment than autumn. This is most likely due to the slow germination of the plant, meaning it does not manage to establish well enough to support itself through the dormant winter months.”

For more information on growing and feeding lucerne, download the AHDB Lucerne Guide from the website.

A further Profitable Protein event will take place at Halfridge Farm in Worcester on Wednesday 19 August. To book a place, contact AHDB Dairy Extension Officer Thom Washbourne on 07773 245031.