By Tim Alexander
BLOOMINGTON, Ill. — A member of the University of Wisconsin-Madison “bean team” stopped by the Illinois Soybean Association (ISA) 2021 Virtual Soybean Summit to share tips and resources for closing the production “yield gap” for soybeans. During a Feb. 10 webinar Dr. Shawn Conley, UW-M professor of agronomy and state soybean small grains specialist, offered the results of recent university soil biology studies along with info on how to access several online tools that can help producers maximize soybean yield.
“From 2015 to 2018 we surveyed farmers from across the north central region, collecting data from over 8,000 farm fields. We have data on more than 600,000 acres of soybean production throughout the Midwest, and we have worked to use this information in a big data approach to help farmers minimize their yield gap, which is the difference between what the genetic yield potential is for soybean and the actual yield,” said Conley, who has authored around 117 papers on soybean productions and delivered more than 700 public presentations.
“I would argue that for much of the north central region that yield potential is around 120-125 bushels per acre,” he added.
Planting date for soybean is crucial and Conley is a strong proponent of early planting. He points to UW-M studies showing soybean yield can be affected by as much as negative-four bushels per acre for each week soybeans are planted after April 20 (in a typical Midwest zone).
Conley also encourages producers to commit to lower seeding rates. “We can put on three times as much yield on (soybean plant) branches than we did 30 years ago,” he said, crediting modern genetics for increasing yield potential of plants.
“Another cool thing that breeders have done over the last 30 years is to increase the yield response to earlier planting. These modern genetics have a much higher yield response to early planting than a few years ago,” the legume expert noted.
Conley recommends producers download the “Bean Cam” free smartphone application, developed around five years ago with funding from the Wisconsin Soybean Marketing Board, to help them evaluate growth stage, stand count, maximum yield estimate and more. Utilizing live video from a smartphone camera, the app can evaluate these factors while plants are in V1 stage in order to help farmers determine if they need to replant soybeans or add more seed in order to close the yield gap.
“If you are out there planting early on 80 percent of the soils in Illinois or Wisconsin and you have 100,000 plants per acre growing, you are basically at 100 percent of your yield potential,” Conley said, adding that he recommends residual herbicides to help combat waterhemp or other weed species. “Even at 50,000 plants per acre that soybean field will canopy. At 50,000 plants per acre we have three times the capacity to put yield on those branches.”
Conley cautioned producers about what he regards as the “soybean flowering fallacy” that promulgates soybeans will not flower until at least June 21. “I think we’ve seen lots of pictures on Twitter that soybeans going in in late March or early April in Illinois are forming flowers the first week in June,” he said, before recommending another WSMB-sponsored app, SporeCaster, which helps producers decide when to spray fungicides for white mold management and other plant maladies. A related free app, SporeBuster, offers quotes for various fungicides based on the price level users select. “When you run the app it tells you which fungicide to apply to achieve the highest level of return on your investment,” said Conley.
A current UW-M project breaks down fungicide and insecticide treatments by state using data gathered in 2019. The data will be utilized to help farmers narrow their soybean yield gap.
“On 47 on-farm plots across the Midwest we saw an average six-bushel yield increase by implementing our approved treatments over referenced treatments. We saw an average increase in net profit of $55 per acre when farmers used our approved treatment over the treatments they had typically been using in their areas,” Conley said. “We are seeing cost savings in some cases through a decrease in seeding rates, but also (through) the advantage of using a foliar fungicide and-or insecticide at R3.”
Conley directed producers who have more questions about his approach to narrowing the soybean yield gap to his website, www.coolbean.info.