Soybean Seeding Rate Calculator
Your Estimated Seeding Rate:
Understanding Soybean Seeding Rates
Determining the optimal soybean seeding rate is crucial for maximizing yield and profitability. Seeding rate refers to the number of seeds planted per unit area, and it's influenced by several factors. An accurate seeding rate helps ensure a desirable plant population, which is the number of plants that successfully emerge and survive in the field.
Key Factors Influencing Seeding Rate:
- Target Plant Population: This is the ideal number of healthy soybean plants you aim to have per acre at harvest. This target can vary based on soybean variety, soil type, planting conditions, and management practices.
- Seed Weight: Also known as "thousand seed weight" (TSW), this is the weight of 1,000 soybean seeds. Heavier seeds generally mean larger seeds, which can impact seeding volume.
- Germination Rate: This is the percentage of seeds that are viable and capable of sprouting under ideal conditions. It's usually determined by a seed lab test.
- Field Survival Rate: This accounts for losses that occur after germination due to environmental factors like soil crusting, insects, diseases, and early-season stress.
Why is the Right Seeding Rate Important?
Planting too few seeds can lead to lower yields due to a sparse stand and increased weed competition. Conversely, planting too many seeds can result in overcrowding, which may lead to taller, weaker plants, increased lodging, and potentially lower yields per plant, while also increasing seed costs unnecessarily.
How the Calculator Works:
This calculator takes your desired target plant population and adjusts it based on the germination rate and field survival rate to determine how many seeds you need to plant. It then uses the seed weight to estimate the total amount of seed needed, typically expressed in pounds per acre.
Example Calculation:
Let's say you aim for a Target Plant Population of 140,000 seeds per acre. Your soybean seed has a Seed Weight of 150 grams per 1000 seeds. The seed lab reported a Germination Rate of 90%, and you anticipate a Field Survival Rate of 85% under your expected conditions.
The calculator will first determine the number of seeds to plant by accounting for germination and survival:
Seeds to Plant = Target Population / (Germination Rate / 100) / (Field Survival Rate / 100)
Seeds to Plant = 140,000 / (0.90) / (0.85) ≈ 172,840 seeds per acre
Then, it converts this seed count to pounds per acre:
Weight per seed = Seed Weight (grams) / 1000
Weight per seed = 150 grams / 1000 = 0.15 grams/seed
Total pounds per acre = (Seeds to Plant * Weight per seed (grams)) / 453.592 (grams per pound)
Total pounds per acre = (172,840 seeds/acre * 0.15 grams/seed) / 453.592 grams/pound ≈ 57.61 pounds per acre
Therefore, based on these inputs, you would need to plant approximately 57.61 pounds of seed per acre to achieve your target population.