Farm Progress Reports


RFR A1543


Ag Engineering/Agronomy, Central Iowa and BioCentury Research Farms




Crops and Soils


As corn and soybean seed prices continue to rise, and grain prices fall, it is important for farmers to find a population that maximizes both yield and profit. Planting too high of a corn population can result in increased barrenness and thus lower yields, but too low of a population also can result in lower yields. Most past research has shown the optimal planting rate for corn yield falls in a range from about 35,000 to 37,000 seeds/acre. Past studies have indicated soybean yields are similar across a wide range of populations, but too low of a population can result in reduced yields and too high of a planting population can reduce profits. A common recommendation is to plant soybeans at a seeding rate that will achieve a final stand of 100,000 plants/acre or more. The objective of these trials was to evaluate what effect planting population would have on corn and soybean yield.