Strive for Uniformity A late-emerging soybean could affect your bottom line BY KRISS NELSON
U
neven seedling emergence in corn will reduce profitability and yield. Less known, however, are the effects of uneven emergence on soybean yields. To better understand this relationship, the Iowa Soybean Association’s (ISA) Research Center for Farming Innovation (RCFI) teamed up with northeast Iowa farmer and agronomist Troy Deutmeyer. Deutmeyer’s research included three locations in Iowa. He marked the soybean plants according to their day of emergence and tracked the plant phenology throughout the season. “We want those soybean plants to emerge within two to at most three days of each other,” Deutmeyer says.
“After this time, we see significant yield loss from plant to plant on the late emergers.” Studies show that late-emerging soybean plants produce 20% fewer pods and have more than 30% fewer threebean pods. Scott Nelson, ISA senior field services program manager, says the study cannot answer the question of how delayed emergence affects final yield. “Early-emerging soybean plants may or may not grow more branches when next to late-emerging plants, for example,” he says. “What is clear, is uneven emergence in soybeans reduces top-end yield as each plant does not contribute equally to yield.”
Georgia farmer Randy Dowdy set the world record for soybean yield in 2019 at 190 bushels an acre. “Emergence is something Randy stresses in his soybean production,” Nelson says.
Achieving uniform emergence Soybean producers should look at achieving uniform plant emergence in the same way they work to attain uniform emergence in corn. The first step is at harvest. “It all starts with the combine path in the fall, making sure we have uniform residue distribution,” says Deutmeyer. Uniform residue distribution will
Troy Deutmeyer worked with ISA’s RCFI team to study effects of uneven emergence in soybean production.
14 | APRIL 2022 | IASOYBEANS.COM
