Research Highlights

Research Highlights
Using New Research Techniques to Tweak Production Systems

Photo: United Soybean Board

By Barb Baylor Anderson

Rapid advances in technology over the last 35 years have led to a doubling of soybean yields across Mississippi. But with that increase came little change in fertilizer use, rising costs for seed technology and the introduction of new crop protection options. As a result, farmers face many decisions as to which inputs to incorporate and which inputs result in significant economic gain.

“Yield gains do not always lead to financial gains when the whole-farm enterprise is considered,” says Wayne Ebelhar, agronomist with Mississippi State University and principal investigator for research into the topic funded by the Mississippi Soybean Promotion Board. “The goal of our comprehensive project was to combine technologies into a management system that would optimize yields and increase profitability and assess the impact of each factor.”

Research in the Corn Belt has previously and successfully used this stepwise technique to create a “high tech” system that methodically removes or adds an input and then evaluates yield gain/loss and quality considerations from each practice along with its economic implications. With use of a similar process in Mississippi, Ebelhar says their team developed the following suggestions that can increase yields and/or reduce input costs:

  • Plant populations can be lowered and still maintain yields in both single-row and twin-row production systems. Dropping from 12 seeds per foot to as low as six seeds per foot maintained yields as long as the reduced stand was uniform. Ebelhar says soybeans have tremendous potential to compensate for less-than-optimum stands with more branching, knowledge that can be used for replant decisions. 
  • Soil testing and scouting are essential for knowing what is going on in a field. Making fertilizer or fungicide applications when soil nutrients are sufficient and no disease is present cost money and offer no benefit. Ebelhar says applying a desiccant may help with ease of harvest but may not be cost effective directly.
  • Twin-row production may not always mean more yield than single-row, but research shows twin-row usually leads to more rapid ground cover and shading of weeds. Ebelhar says this could save farmers one herbicide application and lead to moisture conservation.
  • Drift issues are real and can decrease yields. Researchers found drift was a major issue across much of the state and has led to cultivar shifts even if the technology is not used.
  • Fungicide applications should be made after scouting determines the need. Blanket applications may increase yield a little, but often the increase does not cover the cost.
  • While some disease presence, such as Purple Seed Stain, may result in dockage at the elevator it may not affect seed quality. Appearances can be deceiving.

Ebelhar notes future research could include interaction of planting orientation and seeding rates (whole plots from this study) with herbicide applications and different potential herbicide systems. Research including introduction of maturity groups and plant pathology challenges associated with the effects of agronomic inputs on disease also could further benefit farmers.

“Research is already underway to look at fertility, since yields are much higher today than when most of the research on soil test calibration and correlation was completed,” he says. “There is a big push for uniform soil testing methods since little data is available to support switching methods for the sake of switching without the data to support it.”

Published: Sep 9, 2020

The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.