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Competency Area 5: Seeding Rates and Row Spacing

PO 23. Know recommended seeding rates for major Northeast crops.

Soybeans:

soy seeding rate

The recommended seeding rate depends on planting pattern. The general recommendation is to seed at 180,000 seeds/acre for drilled soybeans and about 160,000 seeds/acre for soybeans in 30-inch row spacing. Soil type is not a major factor in soybean seeding rate recommendations because soybeans fill in so well that they use about the same amount of water, regardless of final stands.

Corn for grain:
The recommended seeding rate for corn grain depends on soil type. Soils that have high water holding capacity should have final stands of about 30,000 plants per acre. Assuming a 90% emergence rate for corn, the actual seeding rate should be about 32,500 seeds/acre (somewhat higher if seeded early under no-till conditions because emergence may be less than 90% but only 31,000 seeds/acre if planted in late May under plowed conditions because emergence will be 95% or higher).  Droughty soils with low water holding capacity should have final stands of only 26,000 plants/acre because droughty conditions set in more easily on these soils. Consequently, seeding rates should be about 30,000 plants/acre on these soils with adjustments made for planting date and soil conditions.

Corn grain vs. corn silage seeding rates:
Silage corn can be seeded at higher rates because dry matter or biomass production responds more favorably to high seeding rates than grain production does. Generally, corn silage should be seeded at about 4,000 more kernels/acre with final stands 3,500 plants/acre higher than corn for grain. Maximum yield for corn silage occurs at final stands of close to 40,000 plants/acre but quality decreases. Consequently, final stands of corn silage should be at 33,000-34,000 plants/acre on soils with high water holding capacity (36,000-37,000 kernel/acre seeding rate with 90% emergence rate) and 26,000- 28,000 plants/acre on droughty soils.

Wheat:
The recommended seeding rate depends on planting date. Wheat is planted anytime from mid- September to early November. Also, wheat tillers profusely if the seeding rate is low, plants can “fill in” and compensate for low final stands. Seeding rates should be about 2 bu/acre for wheat planted before mid-October and 2 ½ bu/acre when planted after mid-October. Growers can fine-tune their seeding rates because seed size varies with many wheat varieties and go with 1.6 million seeds/acre until mid- October and then increase the seeding rate to 2.0 million seeds/acre after that.

Perennials:

  • Alfalfa – 12-15 lbs/acre
  • Red clover – 4-8 lbs/acre
  • Birdsfoot trefoil – 4-6 lbs/acre
  • Timothy – 4-6 lbs/acre
  • Orchardgrass – 4-8 lbs/acre
  • Smooth bromegrass – 5-8 lbs/acre