Shelled corn is the term used to describe whole kernel corn that has been removed from the cob. It is harvested using a large combine machine that cuts the stalks, strips the cobs off the stalk, strips the husk off the ear and then separates the kernels off the cob and spits the chopped stalks and husks and cobs out the back of the machine. The corn is stored in a bin and regularly offloaded to a semi or gravity wagon. Ideally, the corn is left in the field on the stalk to dry to the correct percentage. If it is a wet year, the corn might have to be harvested, and then dried in large gas fired driers. In Illinois, the average corn yield is about 150 bushels per acre, but I don't think you could do it on your own as a do it yourself project.