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Replant soybean acres, or stay with your race plan

Like a Formula 1 driver, where you start on the planting grid can affect success with your soybean crop.

Mindy Ward, Editor, Missouri Ruralist

May 31, 2023

2 Min Read
racetrack toward soybean
DECISION TIME: Farmers have choices every year with their operation — some they are in the driver’s seat on, others it’s Mother Nature. This year, drought conditions plagued some areas during prime soybean growing season. Now, farmers face the option of replanting or staying the course. Mindy Ward and arthobbit/Getty Images

Replanting soybeans is like restarting a race, but behind in the grid, Andre Reis says. Farmers may want to reassess their strategy for success this growing season.

Reis, the new University of Missouri Extension state soybean specialist, says if the soybean replant date is in late May and June, farmers may find “the reduced yield potential may be lower than the field you are trying to fix.”

He looked at MU Soybean Variety Testing legacy data and found an average yield loss of 3.5 bushels per week of delayed planting dates after May 15 across all Missouri production environments. In the southern region of the state, it is closer to 2.6 bushels per week.

On top of the potential yield loss, growers need to account for extra seeds and replanting costs, Reis adds. “Replanting a soybean field is a situation that nobody likes to encounter. An overall assessment of the likelihood of a stand recovery and the implications of a late planting date helps to make the best decision.”

So, what should farmers look for before replating? Here are Reis’ suggestions:

Assess germination. Soybean seeds need water to germinate. The lack of hydration will not allow plants to emerge.

Count plants. Reis says when the initial plan population varies significantly from the targeted seed population, farmers may need to replant. However, pay attention to your soybean variety — it may surprise you. Soybeans have an ability to compensate for low plant stands if environmental stressors stay at bay. “Modern soybean varieties can produce higher yields with a population of as little as 50,000 plants per acre at harvest in southern regions or 75,000 in northern regions,” he notes. Farmers should consider plant stand.

Inspect stand. Reis finds uniformity is key in soybean fields. If the standard deviation of the distance between plants is 4 inches or greater, there is a predicted yield loss of up to 30 bushels per acre. However, if the stand produces plants too close to one another, it can create competition for light and nutrients, which also affect yield.

Poor soybean stands may provide adequate yields without replanting. “It will depend on the growing conditions during the late vegetative and reproductive stages,” Reis says. “High-yield environments are less affected by the initial stand than low-yield environments.

Reis reminds farmers that replanting is, above all, a risk management decision. They need to ask, is it economically better to keep the failed stand, or fully or partially replant it with a lower yield potential?

MU-IPM contributed to this article.

Read more about:

Drought

About the Author

Mindy Ward

Editor, Missouri Ruralist

Mindy resides on a small farm just outside of Holstein, Mo, about 80 miles southwest of St. Louis.

After graduating from the University of Missouri-Columbia with a bachelor’s degree in agricultural journalism, she worked briefly at a public relations firm in Kansas City. Her husband’s career led the couple north to Minnesota.

There, she reported on large-scale production of corn, soybeans, sugar beets, and dairy, as well as, biofuels for The Land. After 10 years, the couple returned to Missouri and she began covering agriculture in the Show-Me State.

“In all my 15 years of writing about agriculture, I have found some of the most progressive thinkers are farmers,” she says. “They are constantly searching for ways to do more with less, improve their land and leave their legacy to the next generation.”

Mindy and her husband, Stacy, together with their daughters, Elisa and Cassidy, operate Showtime Farms in southern Warren County. The family spends a great deal of time caring for and showing Dorset, Oxford and crossbred sheep.

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