Corn yield estimations prior to harvest are helpful in planning harvest operations, including drying, storage and marketing of grain. They may also be useful in making preliminary hybrid selections and buying decisions for next year's crop, as seed-corn discounts are often greater with early purchases. Yield estimate accuracy increases with crop maturity, but early estimates provide more time for developing strategies to deal with the expected volume of grain, and also satisfy a grower's most basic curiosity - how is my corn crop going to do?
General Procedure (see details below.)
For other row widths, divide 6273 by the row width. For example, for 36-inch rows: 1/1000 acre = 6273/36 = 174 in. = 14 ft. 6 in.
Though the original procedure used a broad average of 90,000 kernels per bushel, this is not always the best estimate to use. Hybrids intrinsically differ in kernel size and test weight, and the growing environment also significantly impacts this trait. Much accuracy can be gained in the estimation process if the number of kernels/bu is chosen to better fit the particular hybrid or environment.
Univ. of Illinois. 2005. Estimating corn yields (an online calculator.) Illinois Agronomy Handbook.