Everything you need to know about soybean populations

May 26, 2020

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

This year, you should expect your soybean plants to emerge 15 to 20 days after sowing—a process that normally takes less than a week. This year, producers were able to start earlier than usual because of warmer weather in mid-April. But the colder temperatures in early May slowed down the emergence of soybean plants in some regions. It’s also important to remember that not all soybean varieties respond the same way to plant densities. The most important thing is to seed according to each variety’s recommended plant population!

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!