Everything You Need to Know About Soybean Populations

May 29, 2024

Now that producers are almost finished or done seeding their soybeans, it’s time to take a look at the emergence success, or the number of plants that emerged in relation to seeds planted. Here are some tips to help you get an optimal yield!

Emergence

It takes about 7 to 20 days after planting for soybean plants to emerge. This time varies depending on the soil temperature: the higher the temperature, the faster the germination, the lower the risk of germination problems. We are talking about 7 days if the soil is at 20 °C and 21 days if the soil is at 10 °C. Planting is later than normal this year, so rapid germination can be expected with warming soils. It should also be noted that not all soybean cultivars respond equally to different populations. The most important thing is to sow the recommended population of each variety!

Some stats

Normally, producers can plant between 375,000 and 500,000 seeds per hectare. If they achieve a plant stand of 250,000 to 450,000 plants per hectare (100,000 to 180,000 plants per acre), they’re in good shape! So the target germination rate should be at least 85%.

What if things don’t go as planned?

And what if you don’t get the stand establishment you desire? If you end up with less than 250,000 emerged plants per hectare (100,000 plants per acre), it’s a good idea to replant if you have time. But it’s important to take a good look at things to understand why your seeds didn’t emerge as planned.

Main causes of seed loss

  • Cold snaps

If the temperature drops after planting and the seed absorbs very cold water from the soil within 24 hours of seeding, this can cause a chilling injury.

  • Pests like wireworms.
  • Damping off

Damping off occurs when a disease caused by fungal pathogens affects the root and collar and kills young seedlings. Phytophthora is a common pathogen among soybeans.

  • Seeding depth

Seeding too deep (2 or 2.5 inches) or too shallow (less than 1 inch) can reduce populations at the beginning of the season.

  • Not enough water

What are my options?

It’s not too late to think about replanting! A Prograin representative can help you create a decision tree to identify the problem and explore different action plans.

Get in touch with your local Prograin representative a Prograin representative!