Formulas
- Plants per hectare = plants per meter of row × 10,000 ÷ row spacing in meters (1 hectare = 2.471 acres)
- Seeds to sow = plants ÷ germination rate
- Seed weight = seeds × thousand-seed weight ÷ 1,000,000 (kg)
Example
Soybeans in 50 cm (about 20-inch) rows with 12 plants per meter give 240,000 plants per hectare, or 97,123 per acre. With 85% germination you sow 282,353 seeds per hectare; at 150 g per thousand seeds that is 42.4 kg per hectare, and 423.5 kg for 10 hectares.
Tips
- Use the germination printed on the seed tag, and lower it a little for cold or dry soil.
- Calibrate the planter: count the seeds in a few meters of row after it starts.
Frequently asked questions
How do I convert row spacing in inches?
Multiply inches by 2.54 to get centimeters. 30-inch rows are 76.2 cm; 15-inch rows are 38.1 cm.
Why sow more seeds than plants?
Not every seed germinates and some seedlings die. Dividing by the germination rate makes up for those losses.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.