Western Research and Demonstration Farm
Much of the soybean plant's nitrogen requirement is supplied through nitrogen fixation when atmospheric nitrogen is converted into a usable form for the plant. Nitrogen fixation is critical for producing higher yield in soybean. For nitrogen fixation to occur, nitrogen-fixing bacteria (genus Rhizobium) need to be present in the soil. If soils do not already contain a high population of Rhizobium, these bacteria can be added either as a liquid or granular peat inoculant, or as a peat-based powder. The different forms can be seed applied or used in-furrow.
Iowa State University
DeJong, Joel L. and Roush, Wayne B., "Soybean Yield Response to Rhizobium Inoculation on Converted Grass Pasture" (2012). Iowa State Research Farm Progress Reports. 130.