South Dakota has been asked to participate in a national soybean study as a part of an extension grant from the United Soybean Board (Amplifying Extension Impact: Agronomists Collaboratively Delivering Soybean Best Management Practices. (2019-2022) Seth Naeve (UM), Shawn Conley (UW), and Rachel Vann (NCSU), co-PIs). There are a large number of biological seed treatments (e.g., fungi, amino acids, bacteria) marketed to growers under the premise that this practice will produce a positive ROI due to plant health promoting properties. Growers often purchase these products with the intention of maximizing yield to gain a competitive advantage. The effect of these products on yield, however, is largely undocumented. The effect of biological seed treatments on soybean yield and economic returns is important to understand across a range of production environments. Here, we will evaluate commonly marketed biological seed treatment products in several areas of the U.S. This will help us identify environmental and soil factors where yield response to biological seed treatments is most likely to occur.