pasture grasses

Objective of the Lecture

• Description of Common Pasture Grasses: Focus on sown species in New Zealand.
• Identification: Understanding how to recognize pasture grass plants.
• Management: Importance of understanding adaptation to climatic and soil factors.

Key Factors in Pasture Grass Management

• Climatic Factors: Mainly temperature and moisture.
• Edaphic Factors: Soil fertility and grazing management.
  • Grazing Tolerance: Ability to withstand grazing pressures.
  • Insect Pest Tolerance: Influence on grass plants' persistence.
• Yield and Nutritional Value:
  • Annual Dry Matter Yields: Amount of dry matter produced.
  • Nutritional Characteristics:
  • Metabolizable Energy (ME) value
  • Crude protein content
  • Fiber content
  • Digestibility

Identifying Grass Species

• Importance of Identification: Helps in understanding grass adaptability and management suitability.
• Field Work: Engaging in hands-on identification of grass tillers.
• Resources: Massey University's Pasture Plant Identification website.
• Interactive Learning: "Grasp View" software by the University of Nottingham for enhanced understanding of grass morphology.

Main Grass Species in New Zealand

Ryegrass Overview

• Key Types of Ryegrass:
  • Perennial Ryegrass (Lolium perenne): Most commonly sown; persistent for several years.
  • Annual Ryegrass (Lolium multiflorum): Used for short periods; performs well during one season.
  • Hybrid Ryegrass: Cross between perennial and annual; includes short rotation and long rotation types.
  • Italian Ryegrass: May persist for one or two seasons, suitable for various growing cycles.

Perennial Ryegrass

• Properties:
  • Growth: Emerald green color, shiny leaves with a folded base, sometimes with a purple hue.
  • Soil Fertility: Requires medium to high fertility, optimal Olsen P values around 20-25.
  • Drought Tolerance: Moderate; may struggle in extreme dry conditions.
  • Establishment: Economically viable with various available cultivars.
• Endophytes: Fungi inside the grass important for pest deterrence and overall health.

Cultivar Differences in Ryegrass

• RAGT NZ: Key seed company producing various ryegrass cultivars with distinguishing features.
• Novel Endophytes: Enhancements in pest deterrence and resistance.
• Ploidy Variation: Differences in diploid and tetraploid cultivars affecting growth and persistence.
  • Early flowering (mid to late October) impacts pasture growth profiles.

Alternative Grass Species

• Tall Fescue (Lolium arundinaceum):

  • Characteristics: Tolerant of wet and dry conditions; requires high fertility.
  • Management: More sensitive to grazing; slower establishment.
  • Endophytes: Cultivars available with novel endophytes for pest deterrent effects.

• Cocksfoot (Dactylis glomerata):

  • Characteristics: Persistent in droughts, suited to medium fertility soils.
  • Grazing Conditions: Performs well in both lax and frequent grazing scenarios.

• Brome Species:

  • Includes Grazing Brome (Bromus stamineus), Pasture Brome (Bromus valdivianus), and Prairie Grass (Bromus wildei).
  • Differences: Variability in grazing tolerance and drought resilience.

• Timothy (Phleum pratense):

  • Characteristics: Suitable for summer moisture; high-quality but slow to establish.

• Phalaris (Phalaris aquatica):

  • Properties: Good drought tolerance but can cause health issues in livestock.

Conclusion

• Perennial Ryegrass: Dominant grass species, inexpensive to establish, suitable for various environments in New Zealand.
• Cocksfoot and Alternatives: Viable options when ryegrass fails; each alternative has unique requirements and benefits.

Resources for Further Study

• Textbook References:

  • "New Zealand Pasture and Crop Science"
  • "Pasture and Forage Plants for New Zealand"

• Online Resources:

  • National Forage Variety Trials (www.pbra.co.nz) for comparative yield data.