Late Planting of Soybeans

Suggestions for Late Planting of Soybeans
Growers continue to struggle with rain interfering with planting and spraying operations. Corn is becoming too late to plant because of frost and yield risk.
Questions have been coming into the Extension office regarding alternative crops but our best suggestion would be to move to planting soybeans rather than trying a crop that you do not have experience with. Also, typically an alternative crop does not have a local market and may have to be trucked to another state to be sold. There are also many other complications of alternative crops such as fertility, weeds, insects and disease management requirements.
So as we move to first part of July, we would suggest planting soybean. When planting soybeans at this late date, this would be similar to a double crop situation after wheat.
First, narrow rows are better than wide rows. With this late date, planting soybean plants in narrow rows make better use of space compared to say 30-inch row spacing. We are substituting growth of individual plants by using narrow rows and capturing as much sunlight as possible compared to trying to achieve growth from individual plants in wide rows.
Seeding rates can be the same for both 15-inch and 30-inch rows but please keep in mind the lower germination rates of seed this year. We have had some fields that suffered from poor germination rates resulting in poor soybean stands.
In early July, plant a variety with a Group III soybean maturity to maximize yield. Group II variety will mature too early and Group IV have risk of frost.
If the site was flooded, inoculate the seed the Rhizobium and use a seed treatment to protect plants from seedling diseases. Flooded soils generally have seedling disease problems and Rhizobium levels may be reduced from flooded soils. Be sure to check product labels as some seed treatments can affect the viability of Rhizobium.
For more information, contact Wayne Flanary, Regional Agronomist, University of Missouri Extension at 660-446-3724.