Effect of row spacing and plant stand on soybean yield at five locations in Iowa, 1994-1996. Grain yield did not differ significantly for harvest stands above 100,000 plants per acre in either row spacing. A harvest population of less than 100,000 plants per acre produced a significantly lower yield than stands of 110,000 plants or more. These studies indicate that the producer should plant enough soybean seed to have a harvest stand of at least 100,000 plants per acre. The cost of additional seed, however, must be taken into consideration before planting excessively high plant stands.
Seed companies continue to sell soybean by weight rather than seed count.
The extra 50,000 seeds could plant one-third of an acre. Table 2 shows the different number of seeds per 50-lb bag with different numbers of seeds per pound and the pounds of seed required per acre for three seeding rates. Most commodity soybean varieties produce between 2,500 and 3,500 seeds per pound under normal environmental conditions. Environmental stresses may result in either larger or smaller size seed depending on the time and severity of the stress. Specialty soybeans for food use range from less than 1,500 to more than 6,000 seeds per pound depending on the intended use.