Managing Drought-Stressed Alfalfa

• Drought stress often increases forage quality due to higher leaf-to-stem ratios and nutrient accumulation – higher crude protein and digestibility, especially NDF.
• However, prolonged dryness reduces nodule formation and nitrogen fixation, eventually limiting plant metabolism.

• Harvest only if yield justifies cost and plants are at least 10 inches tall and mid-to-full bloom.
• Cutting at full bloom maximizes yield and allows root reserve replenishment.
• If plants are under 10 inches, delay harvest until adequate growth or rainfall occurs.
• Cutting height should be low for yield but high enough to avoid soil contamination and protect crowns.

1. Remove old growth for low-quality feed, promoting high-quality regrowth.
2. Delay cutting until new stems mature, harvesting both for medium-quality feed.

• Spring-seeded alfalfa may be harvested in fall if growth exceeds 10 inches and timing is at least six weeks before frost.
• Maintain leaf material for photosynthesis and root development.

• Harvest only if yield is economical; quality declines under drought.
• Dry conditions reduce feed quality due to increased fibre levels and energy levels decrease
• Cut at heading stage for best balance of yield and quality.
• Stands under 10 inches can remain unharvested but remove excess growth before winter to prevent snow mold.
• If moisture improves, apply 30–40 lbs inorganic nitrogen to stimulate fall growth.

• Ensure soil fertility is optimal for recovery when moisture returns.

• Regrowth after cutting is vulnerable to pests such as alfalfa weevils.
• Cutting often reduces weevil damage, but monitor regrowth closely under dry conditions.

• Test forage quality before feeding and adjust rations accordingly.