Seeding Rates

Soybeans compensate remarkably well for thin stands by branching. The goal is the most profitable stand — not the most plants.

Final stand vs seeding rate

Seeding rate is what goes in the planter; final stand is what's alive at harvest. Many university trials across the Midwest find that final stands of roughly 100,000–120,000 plants per acre capture nearly all of the yield potential in good conditions, with returns flattening above that. Seed is often one of the biggest per-acre input costs in soybeans, so extra seed has to earn its keep.

Rule of thumb: decide your target final stand first, then work backward through germination and expected emergence to get the seeding rate.

The math

  1. Seeds per acre = target final stand ÷ (germination % × expected emergence/survival %)
  2. Seeds per foot of row = seeds per acre × row width in feet ÷ 43,560
  3. Units needed = seeds per acre × acres ÷ seeds per unit (commonly 140,000)

Example: 120,000 target ÷ (0.92 × 0.85) ≈ 153,500 seeds/A. In 30-inch rows that's about 8.8 seeds per foot, or about 1.1 units per acre.

Open the seeding rate calculator

When to seed higher — or lower

Consider higher rates

  • Late planting or double-crop
  • Poor seedbeds, crusting-prone or cold no-till soils
  • IDC-prone, high-pH fields (higher populations can help)
  • Wide rows where canopy closes slowly
  • Seed with lower germination or vigor

Consider lower rates

  • Fields with a history of white mold
  • Excellent seedbeds and early planting
  • High-yield environments with good branching varieties
  • Very good emergence history with your planter and seed treatment

Row spacing

Narrow rows (15 inches or drilled) close canopy faster, shading weeds and capturing more light. Yield advantages for narrow rows are most consistent in northern areas, with late planting, and with shorter-statured varieties. In 30-inch rows, the plant-to-plant spacing is tighter for the same population, so singulation and even depth matter more. Wider rows improve airflow in white mold–prone fields.

Replant decisions

  • Count live plants in several 1/1000-acre lengths of row (17 ft 5 in for 30-inch rows) or with hoops in drilled beans.
  • Check stand uniformity as well as numbers — large gaps matter more than an even, slightly thin stand.
  • In much of the Midwest, uniform stands of roughly 70,000–75,000 plants per acre or more often don't justify replanting, especially after mid-May.
  • Factor in the yield lost to the later replant date and seed cost before deciding. Check your state's replant guide and any seed replant policy.

Planting Timing

Soil temps and dates.

Break-Even

See what seed costs mean for profit.

Recommendations summarize land-grant university research; optimum rates vary by region, soil and year.