Establishing Alfalfa and Grasses for Hay and Silage

Introduction

• Presenter: Dr. Dan Undersander, Extension Research Forage Agronomist, University of Wisconsin
• Topic: Establishing stands of alfalfa and grasses for hay and silage

Key Considerations for Establishing Stands

1. Soil pH

   • Ideal soil pH: 6.8
   • Low soil pH leads to slower establishment and poorer stands

2. Soil Firmness

   • Firm soil ensures good seed-soil contact for water absorption
   • Loose soil has too much airspace, preventing water uptake

3. Seeding Depth

   • Recommended depth: ¼ to ½ inch
   • Too deep or too shallow affects establishment negatively

Common Causes of Stand Failures

• Low soil pH
• Loose soil
• Improper seeding depth

Establishment Techniques

• Use properly adjusted seeding equipment
• Importance of soil packing demonstrated through field examples

Alfalfa Seed Details

• Seed Coating
  • Types: Clay coating (32% weight), Polymer coating (8-10% weight)
  • Benefits: Holds inoculum, fungicide, minerals, etc.
  • Check seed tag for inert material percentage

Germination Process

1. Water Uptake (Imbibition)

   • Seed swells and coat cracks
   • Partial water uptake can lead to seed death

2. Radical Growth

   • Radical grows down, anchoring itself
   • Hook pushes up, cotyledons emerge above soil
   • Initial leaf: Mono foliate (single leaf), Subsequent leaves: Trifoliate (three leaflets)

Leaf Staging for Herbicides

• Cotyledon and mono foliate leaves do not count
• Staging based on fully expanded trifoliate leaves

Development of Crown

• Crown formation indicates perenniality
• Crown forms at 3-4 inches height
• Crown development ensures winter survival

Growth and Regrowth

• Regrowth from buds on the crown or axillary buds if cut high
• Healthy crop has good crown development just below soil surface

Winter Hardiness

• Winter hardiness reduces winter kill and injury
• Recommended varieties: Winter survival score ≤ 2
• Monitor spring stands for winter injury indicators
• Winter hardy varieties are crucial for late fall cutting

Seeding Rate and Calibration

• Calibration of seeding equipment is critical
• Recommended seeding rate: 12 lbs/acre
• Higher seeding rates lead to higher initial plant numbers but similar fall stands
• Risks of higher rates: Increased cost, potential loss of disease-resistant plants

Recommended Resources

• Available websites for variety trials and updates
• Select premium varieties for best results

Dr. Dan emphasized the practical steps and considerations essential for successful alfalfa and grass establishment and the importance of selecting appropriate varieties and maintaining proper seeding practices.