Research Highlights

Maximizing Yield Through Bigger Management Focus

Barb Baylor Anderson

North Carolina farmers traditionally plant soybeans during a wide window stretching from March to August, as well as across a broad range of maturity groups II through VIII. As such, a more strategic approach to planting date and maturity group selection may help maximize yields.

“While weather plays a large role in which maturity group by planting date combination will maximize yield, the more that is understood about the relationship among these parameters, the greater the likelihood of increasing yields,” says Rachel Vann, North Carolina State University Extension soybean specialist, and principal investigator for the research project funded by the North Carolina Soybean Producers Association. NCSPA is funding trials to evaluate optimum maturity group and seeding rates across various planting dates.

In 2019, trials were established at five locations statewide with planting dates ranging from mid-March through late-July. A soybean variety from each maturity group II through VIII was planted on each of the selected planting dates. Within each maturity group and planting date combination, five seeding rates were compared ranging from 75,000 to 175,000 seeds per acre.

“The widespread drought across North Carolina from late August through early October 2019 had an inevitable impact on yields,” says Vann. “We would like three-plus years of data that capture that kind of environmental variability before we can make robust recommendations to change a grower’s standard practice. But a couple of strong trends stood out in 2019.”

First, Vann notes earlier maturing varieties (II-III) were not the top performers at planting dates before mid-April. In addition, really late planting dates showed that as long as earlier maturing (II-III) varieties were avoided, farmers had flexibility in what maturity group to use. Overall, Vann says the highest yields were group IVs and Vs planted late April through late May. In double-crop planting situations in June, soybean yield was optimized with group IV varieties.

“The trial will be conducted a minimum of two more years. We have three locations across the state in 2020,” says Vann. “We have a graduate student managing this project, and the data from 2019 and 2020 will be the foundation of his master’s thesis.” 

Vann says as North Carolina farmers put more of a management emphasis on soybeans, she anticipates a broader range of planting dates and a willingness to invest more in soybean acres.

“We hope the results from this research will help growers realize that thinking outside the box on soybean management in our state may result in yield benefits across the Southeast,” she says. 

Photo: United Soybean Board

Published: Jul 16, 2020