Plant 1 to 1.5 inches deep. Planting 1 inch or less increases the likelihood of soybean seed not germinating due to cooler temperatures or lack of moisture. Soybeans need to take in 50 percent of their weight during the germination process. By not having the proper planting depth, you risk seeds not fully germinating or not having enough moisture to continue to grow. By planting 1 to 1.5 inches deep you increase the probability of having adequate moisture for germination and early season growth.
Plant when soil temperatures are 55°F or more, or when air and soil temperatures will be increasing. Soybeans can germinate with soil temperatures at 50°F, but are more consistent at 55°F or more. By planting in cooler soil temperatures, you increase the likelihood of Imbibitional Chilling Injury or Cold Shock Syndrome. (Yes, soybeans can get this too). Cool, wet soils (less than 60°F) increase the likelihood of seedling succumbing to Pythium and Fusarium. (Cool, wet soils also increase the potential for Sudden Death Syndrome [SDS] infecting the plant.)
If planting early, use a quality seed treatment. A quality seed treatment that contains an insecticide will help with germination and protect the seed from early to mid-season insects such as Bean Leaf Beetle, Seed Corn Maggot, Soybean Aphids and Soybean Cyst Nematodes. As stated previously, seed treatments help with cool season seedling diseases such as Fusarium, (early infection of SDS), Pythium and warm season diseases such as Phytophthora and Rhizoctonia. Research has also shown that treated soybeans tend to have increased plant population of 12-20,000 versus untreated soybeans. Having a product that helps seedlings survive is especially critical when dealing with soybean seeds that have reduced germination percentages like we have this year compared to other years. Not all seed treatments are equal — just because something has a pretty color does not mean it is the best investment.
Recommended seeding rates are 140,000 to 150,000 seeds in a 30-inch row. Soybeans can yield with less than 140-150,000 seeds planted, however, the issues that suggest maintaining a higher seeding rate are:
• Less than ideal planting seedbed
• Reduced Germination Scores/Percentages
• Wildlife i.e. Geese, Deer, etc.
• Seed and Seedling diseases
• Soil Types
If you have questions regarding this or other Agronomic issues, contact your local Dairyland Seed Representative. Stay safe and have a successful planting season.