Many of us are looking forward to pulling into that first corn field with a combine this fall and see the results of all our hard work, and finally find out how Mother Nature treated us this year. We get asked a lot about estimating corn yield well before the combine gets to the field. It is not an easy task, and many of us hesitate to “stick our neck out” too far due to all the variables in each field. But, there are some simple calculations that you can use to at least get a relative sense of what your fields may yield.
A bushel of corn weighs 56 lbs. There are approximately 90,000 kernels per bushel – if you have “average sized” kernels.
By counting the plant population (ears per acre), and counting the average kernels per ear (girth X length), you can get a rough estimation of yield. As an example, a 30,000 plant population with an average of 600 kernels per ear should equal ~200 bu/A.
Proper yield determination depends on collecting enough counts that reflect the varying field conditions. It is also dependent on average seed size. Seed size and weight can vary by hybrid and condition. Seed weight can vary from over 110,000 kernels per bushel all the way to 70,000 kernels per bushel.
Remember, estimating yield is very relative prior to actually harvesting the field, but you can get a good sense of your better fields and your poorer fields prior to harvest with a little time and effort.