As the yield goal is increased, higher rates of some nutrients, such as nitrogen, will be recommended, and some laboratories may recommend adding other nutrients such as phosphorus, potassium or the micronutrients. In practice, most producers probably set their yield goals too high. A yield goal that is 20 bushels too high can result in excessive nitrogen applications and reduced net return from the crop, as well as wasting energy and increasing potential pollution of surface and ground water. A common rule of thumb is to plant 15 percent more viable kernels than the desired plant population to account for attrition in germination, emergence, and later growth stages. A farmer should know what his yields have been field by field.
Past yields are the starting point in setting yield goals.
But past yields may be too low for a goal under favorable conditions with improved practices. Perhaps 10 to 15 bushels per acre were lost due to poor rootworm control or failure to treat first brood corn borers. Or herbicides were poorly activated, and weeds reduced yields. Maybe you are changing to a new hybrid with higher yield potential. Consideration of all such factors over several years will result in the most realistic goals.