How far should we go to detect subtle biostimulant seed treatment impacts on soybean seed yield?

Plain Language Summary Biostimulant seed treatments (BSTs) are products used in farming that claim to help crops, such as soybean, grow better and produce more. While the agricultural industry surrounding these products is growing, research shows that BSTs often do not lead to noticeable increases in soybean yields in the United States. This study examined how many test sites would be needed to detect even small improvements in yield. The results showed that detecting a very small benefit (0.5 bu ac −1 yield increase) would require >200 test locations, which would take a lot of time, space, money, and effort. Because of this, researchers and farmers are encouraged to think carefully before investing in these products. If farmers still want to try them, they should run their own small‐scale tests and share the results with others. Overall, the study suggests that public research money might be better spent on other farming innovations that offer clearer benefits.