Birdsfoot Trefoil Seed Production
Introduction
Birdsfoot trefoil seed has a strong market demand, but successful production requires careful management and adaptation to local conditions. Production involves three phases:
  1. Pre-establishment period
  2. Establishment year
  3. Subsequent production years
 
Pre-Establishment Year
Site Selection
  • Choose fields free of quackgrass, clover, and other perennial weeds.
  • Prefer clay or loam soils with good water-holding capacity.
  • For pedigreed seed, follow Canadian Seed Growers’ Association for isolation requirements.
Site Preparation
  • Eliminate perennial weeds (quackgrass, Canada Thistle, sowthistle and dandelions) before seeding; control is costly after establishment.
  • Conduct a soil test to determine fertilizer requirements for the establishment year.
 
Establishment Year
Fertilization
  • Apply phosphate, potassium, and sulphur as per soil test recommendations.
  • Broadcast fertilizer prior to seeding; avoid application on frozen soils.
General Fertilizer Guidelines:
Stand Type
P₂O₅
K₂O
S
New Stands
54–76 lb/ac
58–152 lb/ac
27 lb/ac
Established Stands
40–54 lb/ac
40–98 lb/ac
27 lb/ac
(Metric equivalents: P₂O₅: 60–85 kg/ha; K₂O: 65–170 kg/ha; S: 30 kg/ha)
Weed Control
  • Pre-plant:
    • Eptam for grass and broadleaf weeds (no companion crop).
    • Avadex BW for wild oats when seeding with barley, wheat, flax, or canola.
  • Post-emergent:
    • 2,4-DB for broadleaf weeds in seeding year.
    • Princep Nine-T, Simazine 80W, or Kerb for established stands.
  • Refer to Guide to Crop Protection for current recommendations.
Inoculation
  • Use birdsfoot trefoil-specific inoculum; apply twice the normal rate for first-time sowing.
  • Preferred methods:
    • Slurry: Mix inoculum with water and coat seed evenly.
    • Adhesive solution: Add corn syrup (2 tbsp per quart water) for better adhesion.
  • Avoid dry application; pre-inoculated seed is an option if properly stored. If using dry inoculum use 2-3 times the normal rate. 
Seeding
  • If EPTC is applied, seed without a companion crop.
  • If using a companion crop, choose a low-competition species like flax.
  • Seeding rate: 1–2 lb/ac (1–2 kg/ha).
 
Production Years
Roguing
Remove undesirable weeds (e.g., sweet clover) to maintain seed purity.
Pollination
  • Ensure adequate bee populations for pollination.
  • Recommended: 1–2 colonies per acre (2–5 hives per hectare).
  • Wild pollinators are effective near bushland; otherwise, arrange hives with local beekeepers.
Harvesting
  • Harvest when ⅔–¾ of pods are brown, before excessive shattering.
  • Best method: Swath slightly damp to reduce shatter, then combine after 2–5 days.
  • Expect challenges in separation due to small, light seeds—clean further at seed plant.
 
Additional Information
Consult seed trade companies for marketing opportunities and production advice.