Lucerne, Easy

Barenbrug has developed Yellow Jacket Nitrogenerator, a seed enhancement which makes it possible to place Rhizobium bacteria directly on the seed. This seed saves labour and increases the certainty of optimal crop establishment. Yellow Jacket Nitrogenerator embeds bacteria in a polymer matrix around the seed. Extra nutrients and preservatives have been added to this coating to increase shelf life.


Crop management

Apart from choosing lucerne seed with Yellow Jacket Nitrogenerator, the right soil type, optimal fertilisation and correct harvesting methods will contribute to high forage yields. This crop management manual provides you with the necessary information to get the most out of your Yellow Jacket Nitrogenerator lucerne seed.

Establishing a new field

Field requirements 


The pH-KCl on sandy soils > 5.5

The pH-KCl on clay soils > 6.0

Weed pressure

Select field with low weed pressure.

Level of drainage Well drained
Soil structure

Loosen up compressed soil. before sowing, make top soil flat and fine.


> 1 year no lucerne grown on the field.

Soil condition

No Rhizobium bacteria need to be present in soil.


Read more about field preparation here.



Sowing recommendations

Sowing period  Mid-March to end of August After sowing in springtime, up to two cuts can be harvested in sowing year.
Seed rate 25 - 30 kg/ha Can be mixed with Trifolium alexandrinum (25 - 30 kg lucerne + 5 kg Trifolium  alexandrinum)
Sowing depth 1 - 2 cm  
Row distance

8 - 12.5 cm

Use narrow row distance to supress weeds.

Manually add Rhizobia bacteria


Not needed due to the Yellow Jacket Rhozibium seed coating.


Read more about sowing here.



Fertilization recommendations per year per hectare*

Lime (CaCO3) Apply lime for minimum pH of 5.5 on sandy soils and 6.0 on clay soils.
Nitrogen (N)

No N fertilizer required. Rhizobia bacteria will supply 350 kg N/ha/year.

Phosphorus (P) 80 - 110 kg P2O5/ha on sandy and clay soils.
Potassium (K)

260 - 300 kg K/ha on sandy soil.

235 - 70 kg K/ha on clay soil.
Magnesium (Mg)

50 kg MgO/ha only on sandy soil.

* Perform soil analysis for specific recommendations, including Sulphur (S), Molybdenum (Mo) and Boron (B).


Read more about fertilization here.

Weeds and pests control

Weeds and pests control recommendations

Mechanical  control

Control the weeds by mowing/topping

if they grow above the lucerne.

Avoid bare spots: don’t cut lucerne too short.
Avoid damage from traffic by using low pressure tires.

Chemical control

Contact local distributor or advisory service for available products.
Natural disease resistance

Use disease and nematode resistant varieties (Artemis, Alexis).


Read more about diseases here.

Read more about nematodes here.


Dry matter yield

Dry matter yield first year

6- 9 tonnes (spring sowing)

Up to 10% higher than non-coated seed.
Dry matter yield second year Second year 12 - 17 tonnes


Harvesting recommendations

Moment of harvest

Cut at 5 - 10 % of flowering plants.

Weather conditions Cut at dry weather conditions only.
Stubble length 7 - 10 cm. Lower cutting heights kills new sprouts.
Recovery time Lucerne needs to re-grow up to 10 – 15 cm before winter strikes.
Reduce leaf loss

Cut with mower + roller conditioner.

After cut before winter strikes.


Reliable silage additives are recommended to reduce silage quality loss.

Compress and close silage clamp as fast as possible!


Read more about harvesting here.

Nutritional aspects

Nutritional aspects lucerne silage

Lucerne silage Early cut* Normal cut
Crude protein (g/kg dm) 210 172
Crude fibre (g/kg dm) 228 303
Crude ash (g/kg dm)        139 119
Digestibility organic matter (%)



VEM/Mj Nel/ ME



Dry matter intake (kg)



*Yellow Jacket Lucerne varieties can handle a pre-bloom early cut for higher feed quality.


Read more about the excellent feed value of lucerne here.


Where to buy?

Where can you buy Yellow Jacket Nitrogenerator?