Alfalfa Pure Live Seed Seeding Rate Calculator
Calculate alfalfa pure live seed seeding rate in pounds per acre from a target live seed rate, with bulk pounds and bag counts.
How This Calculation Works
Bulk pounds per acre equals the target live seeds per acre divided by seeds per pound, then divided by the pure live seed fraction. Alfalfa has about 200,000 seeds per pound, so 5 million live seeds per acre needs about 28 pounds of bulk seed at 89 percent PLS. Pure live seed is the product of purity and germination percentages.
Field Calibration & Rate Reference Chart
| Species | Seeds/lb | Target seeds/ac | Bulk lb/ac |
|---|---|---|---|
| Tall fescue | 227,000 | 3,000,000 | 15 |
| Kentucky bluegrass | 1,100,000 | 1,500,000 | 2 |
| Perennial ryegrass | 227,000 | 4,000,000 | 20 |
| Bermudagrass hulled | 1,900,000 | 2,000,000 | 1 |
| Bermudagrass unhulled | 800,000 | 2,000,000 | 3 |
| Alfalfa | 200,000 | 5,000,000 | 28 |
| Winter wheat | 12,000 | 1,200,000 | 105 |
| Soybean | 2,800 | 160,000 | 63 |
| Corn | 1,400 | 34,000 | 27 |
| Cereal rye | 18,000 | 1,200,000 | 73 |
Common Questions
How much alfalfa seed per acre?
Pure live seed rates run 12 to 20 pounds per acre for a solid stand, which translates to higher bulk weights depending on the seed tag. Adjust for the pure live seed percentage. Higher rates help in less-than-ideal seedbeds.
What is pure live seed and why does it matter for alfalfa?
Pure live seed is the percentage of the bag that is viable, pure seed, calculated as purity times germination. Because alfalfa seed is costly, buying on PLS ensures you get the stand you pay for. A low PLS means a higher bulk rate.
Do I need to inoculate alfalfa seed?
Yes, alfalfa needs rhizobium bacteria to fix nitrogen, and the correct strain is specific to alfalfa. Many seeds come pre-inoculated, but check the tag and the expiration. Reinoculate if the seed is old or the coating is damaged.
How deep should I plant alfalfa?
Plant alfalfa a quarter to a half inch deep into a firm seedbed. Deeper planting reduces emergence because the small seed lacks the reserves to reach the surface. Press the seedbed before and after seeding for good contact.