Protecting Your Alfalfa
Properly managed and cropped correctly, a stand of alfalfa can last for 3 to 5 years. Here are some recommendations to help prepare your alfalfa before winter and ensure its survival.
- Height of cut: Alfalfa must not be cut below 6 to 7 cm, or it will impact regrowth. If alfalfa is cut shorter, the harvesting machine can damage the crop and limit the regrow between each cut and or for the following spring.
- Frequency of cutting: Wait 4 to 6 weeks between harvests depending on the climate Wait minimum 4 (in the south) to 6 weeks (in the north) to favour the regrow between 2 cuts and in the spring.
- Let alfalfa flower once a year: Alfalfa renews its roots stocks from 30 cm stage to flowering. By letting the alfalfa flower once a year it will enable it to make enough nutrient stocks to face winter and to regrow in spring.
- Last cut 3 to 5 weeks between the first frosts: The last cut should be done 3 to 5 weeks before the first frosts/. This will protect regrowth in spring and help the transfer of energy stocks to the roots.
Spring Fertilizer Application
To maximise your production potential it is very important to manage fertilisation of the crop to favour the perennity of your alfalfa crop. Of special note is potassium. This is a crucial element for alfalfa perennity at vegetative restart. Alfalfa needs 30 kg/ha of potassium per T of dry matter produced.
Calculate the of potassium needs of alfalfa based on potential of the crop, soil analysis and previous crop restitution.
Without any soil analysis, add:
- 150 kg/ha for a potential of 12 T of dry matter/ha
- 300 to 350 kg/ha for a potential of 20 T of dry matter/ha
- Sulfur-potassium has to be divided. For more than 200 kg/ha, add in two times at spring.
- Alfalfa needs good bioavailability of phosphorus to develop well and preserve its roots system.
- Calculate the potassium needs of alfalfa based on soil analysis and previous crop restitution.
If no soil analysis is available, add 70 to 80 kg/ha. Phosphorus should be added in spring when alfalfa restarts.
- Alfalfa needs 50 kg/ha of sulfur at vegetative restart in spring.
To get agronomic advice or find seed, contact find your local MAS Seeds representative.