Over the past two decades, soybean seeding rates have fallen in the United States. This has coincided with shifts in planting method, seed technologies, and seed costs, and could have implications for yields and profitability. This paper examines determinants of seeding rates and the impacts of seeding rates on seed costs, yields, and net returns. We find that the use of genetically engineered seed and conventional planters, as well as earlier planting dates, are all associated with reduced seeding rates. Reduced seeding rates lower seed costs by $1-$4 per 10,000 seed reduction, although they are not associated with yield or net returns in most years. By contrast, the technologies associated with reduced seeding rate, such as conventional planters, are strongly associated with increases in yield and returns.
