Sorghum-Sudan Grass Hybrids

 Sorghum-Sudan Grass Hybrids for Dryland Farming in Alberta’s Special Areas

Sorghum-Sudan grass hybrids (Sorghum bicolor × Sorghum sudanense) are high-yielding, warm-season annual forages that thrive in dryland conditions, making them well-suited for Alberta’s Special Areas. These hybrids combine the drought tolerance of sorghum with the rapid regrowth and forage quality of Sudan grass, providing a reliable source of forage for grazing, silage, green chop, or hay.

They are an excellent option for mixed farming systems that integrate livestock and crop production.

Seed Selection

• Super Sweet Sudan (SSS)
  • High sugar content and palatability.
  • Produces fine-stemmed, high-quality forage suitable for both grazing and hay.
  • Ideal for multiple cuttings, with rapid regrowth after harvest.
• Piper Sudan Grass
  • Provides high yield and excellent regrowth potential.
  • Produces finer stems than most sorghum hybrids, making it better for hay.
  • Good choice for summer grazing and green chop.
• Greentreat BMR (Brown Midrib)
  • Improved digestibility due to reduced lignin content.
  • Higher energy and feeding value, making it ideal for dairy and beef cattle.
  • Better feed efficiency and reduced risk of bloat.
• Sorghum-Sudan Hybrid II
  • Highly productive with excellent drought tolerance.
  • Ideal for silage or green chop with multiple cutting potential.
  • Good regrowth after grazing or cutting.

Factors to Consider in Seed Selection:

• BMR (Brown Midrib) Trait: Lower lignin content improves digestibility and increases energy value.
• Disease Resistance: Look for hybrids with resistance to leaf blights and anthracnose.
• Regrowth Potential: Multiple cuttings are possible with varieties that regrow rapidly after harvest.
• End Use: Select varieties suited for grazing, silage, or hay depending on the intended use.

Planting Guidelines

Site Preparation:

• Weed Control: Eliminate perennial weeds before planting using glyphosate or mechanical cultivation.
• Soil Testing: Conduct a soil test to assess nutrient availability, particularly nitrogen and phosphorus levels.
• Seedbed Preparation: Create a fine, firm seedbed to ensure good seed-to-soil contact and uniform germination.

Seeding Time:

• Optimal Planting Window: Late May to early June, when soil temperatures consistently reach 15°C (60°F) or higher.
• Emergency Planting: Can be planted as late as mid-July if moisture is available, though yield potential will be reduced.

Seeding Rate:

• Drilled: 20–25 lbs/acre for drilled planting.
• Broadcast: 25–30 lbs/acre to compensate for lower seed-to-soil contact.

Seeding Depth:

• Plant at ¾–1 inch depth in moist soil.
• Avoid planting deeper than 1½ inches, as emergence may be delayed or reduced.

Row Spacing:

• Narrow Rows (6–8 inches): Ideal for silage or green chop.
• Wider Rows (20–30 inches): Better for grazing systems as it allows for easy livestock movement and access.

Fertilization and Soil Management

Nutrient Requirements:

• Nitrogen (N):
  • Sorghum-Sudan hybrids are heavy nitrogen feeders. Apply 50–80 lbs/acre at planting.
  • For multiple cuttings, top-dress with 40–60 lbs/acre after each harvest to encourage regrowth.
• Phosphorus (P):
  • Apply 20–40 lbs/acre to promote strong root development and early growth.
• Potassium (K):
  • Required for plant vigor and drought resistance. Apply 30–50 lbs/acre if soil tests indicate deficiency.
• Sulfur (S):
  • Essential for protein synthesis and yield. Apply 10–15 lbs/acre in sandy or low-organic matter soils.

Fertilizer Timing:

• Pre-Plant Application: Incorporate nitrogen and phosphorus before planting.
• Side-Dress Nitrogen: Apply after first cutting or 30 days after emergence to maintain high forage yields.

Growing and Management Practices

Weed and Pest Control:

• Pre-Plant Control: Use glyphosate or tillage to manage weeds before planting.
• Post-Emergence Control:
  • Atrazine can be applied early post-emergence to control broadleaf weeds.
  • Rotary hoeing or light cultivation can suppress weeds in early growth stages.
• Insect Control:
  • Monitor for aphids and leafhoppers during the growing season.
  • Consider insecticide applications if infestations exceed economic thresholds.

Grazing and Cutting Management:

• First Grazing or Cutting:
  • Begin grazing or cutting when the plants reach 18–24 inches in height.
  • Leave a stubble height of 6–8 inches to promote rapid regrowth.
• Subsequent Cuttings:
  • Allow 4–6 weeks between grazing or cutting for optimal regrowth.
  • Avoid grazing after frost, as prussic acid levels can become toxic to livestock.
• Rotational Grazing:
  • Use high-stock-density grazing with 24–48 hour paddock moves to maximize forage utilization.
  • Rest periods between grazing should be 30–40 days, depending on regrowth conditions.

Drought Management:

• Sorghum-Sudan hybrids are drought-tolerant but will enter dormancy under prolonged drought.
• Grazing pressure should be reduced during periods of low moisture to allow for regrowth.

Harvesting and Storage

Silage Production:

• Harvest Timing: Ideal moisture content for silage is 65–70% moisture (soft dough stage).
• Packing and Storage:
  • Pack silage thoroughly to exclude air and prevent spoilage.
  • Cover with plastic and weigh down to maintain anaerobic conditions.

Hay and Green Chop:

• Cutting Stage: Cut at boot stage for highest forage quality.
• Moisture Content: Bale at 18–20% moisture to prevent spoilage.
• Drying Time: Sorghum-Sudan grass hybrids require longer drying time than traditional hay due to thicker stems.

Grazing Residue Management:

• Residue should be grazed down to 6–8 inches to encourage regrowth.
• Avoid overgrazing, as it weakens the plant and reduces subsequent regrowth potential.

Resources and Support for Farmers

Government and Industry Support:

• Alberta Agriculture and Irrigation (AFSC): Provides insurance programs and forage risk management options.
• Canadian Forage and Grassland Association (CFGA): Offers research and technical support on forage production and management.
• Western Forage Beef Group: Conducts research on annual forages and grazing systems suitable for Alberta.

Extension Services and Expertise:

• Agricultural Fieldmen in Special Areas: Provide assistance with forage crop selection and grazing strategies.
• Alberta Ag-Info Centre: Offers resources on pest management, soil fertility, and forage agronomy.

Financial Assistance Programs:

• On-Farm Climate Action Fund (OFCAF): Supports improved rotational grazing and cover cropping practices.
• Canadian Agricultural Partnership (CAP): Funds projects to enhance forage productivity and soil conservation.

Conclusion

Sorghum-Sudan grass hybrids offer a versatile, high-yield forage option for dryland farming operations in Alberta’s Special Areas. Their rapid growth, drought tolerance, and multi-cut potential make them ideal for silage, grazing, and hay production. By selecting appropriate varieties, following sound planting and management practices, and utilizing available resources, producers can maximize forage yield and quality while improving the resilience of their operations.