Injecting fertilizer is usually the most economical way, and you'd get the most bang for your buck, if all the conditions were right. We used to spray nitrogen just as soon as the corn got up and shaded the alley. I still think that's the way you'll get the best yields, because the roots get it immediately, and it's right there when the corn needs it. If you wait until the corn shades out, you don't lose as much through volatilization. Nutrient loss is limited, but not eliminated.
Animal manures are unavailable as a supplemental source of nitrogen.
He's anticipating a need for about 150 pounds to reach his goal of about 120 bushels. The PSNT procedure has been shown to be effective in Virginia and surrounding states for identifying fields that do not need additional nitrogen fertilization at sidedress. A starter-band nitrogen application can be used to get the corn started, and the PSNT can be used to see if sidedress nitrogen is needed. The PSNT more closely identifies the need, or lack thereof, or supplemental nitrogen fertilization. Fertilizer efficiency is going to affect the bottom line more than ever this year.