Several soybean cultivars ranging from early Maturity Group III to late Maturity Group IV were seeded over three environments into no-till conditions in 19-cm rows at plant densities from 30,000 to 470,000 seeds ha^-1 to determine seed vigor effect on minimum density needed for maximum yield. Seed vigor had no effect on seed germination or harvested plant density in any of the environments or cultivars. Uniform plant densities as low as 99,000 plants ha^-1 allowed later maturing cultivars to achieve maximum yields, depending on the regression equation used to fit the data. Higher plant densities were required for maximum yield in earlier maturing cultivars and later planting dates. Seed vigor was not a factor in seed germination, final stand or yield. Uniform plant densities at rates lower than currently recommended can achieve maximum yield.