Agriculture

• Small debris (grass clumps, stones, garbage) disrupts seed and fertilizer placement and smothers growth.
• Large debris (trees, posts, large stones) restricts field operations and must be removed.
• Drag bars (I-beams and old grader blades) can help collect debris and control woody growth.
• Burning can clear vegetation and release nutrients but causes up to 90% nitrogen and sulphur loss.

• Wetland species (cattails, reed canary grass, smartweed, kochia) may be fed cautiously; some pose nutritional or toxicity risks.
• Reed Canarygrass – anti-nutritive alkaloids
• Smartweed (Lady’s Thumb) – photosensitivity
• Kochia – high in salts
• Burning reduces wetland species and promotes native forage regrowth.
• New weeds (e.g., leafy spurge) may appear post-flooding; monitor and control through herbicides or cultural practices grazing or tillage). Repeat monitoring is essential.

• Drag bars help level soil and remove trash.
• Crusting issues: Use a nurse crop or till to mix silt with topsoil.
• Nutrient impact: Flooding can leach nitrogen, sulphur, and phosphorus. Soil testing is critical before reseeding.

• Identify correctly: Saline soils have high soluble salts (sodium chloride and calcium sulphate); sodic soils have high pH (>8.5) and poor structure – prone to hard pan.
• Avoid deep tillage in saline areas; focus on moisture and weed control.
• Seeding tips:
• Do not deep till – can bring salts to the surface
• Control weeds prior to seeding
• Seed shallow in early spring.
• Double seeding rate under poor conditions.
• Use mixes suited for saline soils (e.g., tall wheatgrass, slender wheatgrass, tall fescue).
• Expect reduced production and delayed maturity.

• Nutrient Loss:
• Nitrogen and sulphur leach easily; nitrogen also lost through denitrification in saturated soils.
• Prolonged flooding reduces sulphur levels and stresses beneficial fungi (mycorrhizae), limiting phosphorus uptake.
• Mycorrhizal Recovery:
• Populations rebuild slowly after plant death; phosphorus fertilization near seed improves early growth.
• Recommendations:
• Conduct soil tests when soils are dry enough for access.
• Apply fertilizers based on test results to improve establishment and forage quality.

• Flooding kills nitrogen-fixing bacteria (rhizobia); inoculate all legume seeds before planting.
• Storage:
• Inoculants remain viable on seed for a season if stored cool and dry.
• Seeding Practices:
• Incorporate seeds promptly after broadcasting (harrowing or packing) to protect inoculants.
• Avoid broadcasting on thatch without incorporation—germination and inoculant survival will be poor.

• Drill Seeding
• Most reliable method for forage establishment.
• Ensures good seed-to-soil contact and protects legume inoculants, especially for dormant plantings.
• Broadcast Seeding
• Common in Manitoba; effective on tilled soils with proper weed control and seed incorporation (harrowing or rolling).
• Incorporation is critical when seeding on sod or thatch; options include aggressive harrowing or Aerway passes.
• Poor incorporation leads to inconsistent germination.
• Aerial Seeding
• High-risk option for inaccessible wet fields.
• Only recommended if seeds can be incorporated promptly after application.

• Target 30–40 seedlings per square foot for new stands.
• Increase seeding rate to compensate for poor soil contact, hard seed, pests, and uneven germination.
• Thickening existing stands is difficult unless suppressed by herbicide or severe overgrazing.

• Wait Period: 12 months before reseeding alfalfa into older stands; use this time for summer fallow or another crop (avoid fallow in saline areas).
• Factors Affecting Autotoxicity:
• Stand Age: No issue in stands <24 months old; older stands require waiting period.
• Stand Density: Wider spacing reduces toxin impact; reseeding may work as a short-term fix.
• Flood Duration & Soil Type: Toxin is water-soluble; prolonged flooding or high water movement reduces effect.
• Tillage: Mixing soil accelerates toxin breakdown.
• Delayed Seeding: Slight improvement; best used as a temporary measure.

• Choose seeding method based on field conditions and accessibility.
• Incorporate seed properly for broadcast or aerial applications.
• Adjust seeding rates for establishment challenges.
• Manage alfalfa autotoxicity through timing, crop rotation, and soil preparation.