Corn plants use 75% of their annual nitrogen needs after V10. By waiting until mid-season, you have time to evaluate nitrate needs and apply more or less UAN to minimize costs while maintaining yield potential.
N efficiency is the key. It takes 1.1 units of N to produce a bushel corn. That's a combination of the "free" mineralized N and supplied N. Too often, we provide the full amount of needed nitrogen with our pre-plant applications. However, with strong mineralization we can get 20-50 lbs of free N. Our goal is to manage nitrogen with later applications that allow us to lower the Nitrogen Use Efficiency ration to .7. That lowers input costs while maintaining full yield potential.
360 Y-DROP SIDEDRESS
Once you understand that nitrogen moves vertically - not laterally - it is easy to understand why it is critical to place nitrogen as close to the root zone as possible. Only about 30% of broadcast urea lands over the root zone. And with coulter application systems, roots must grow into the nitrgen channel that sits 15" away from the corn plant - that takes time and moisture. Improved efficiency and rapid response comes from placement directly over the root mass.
For optimum pest control, you have to hit the target. For fungicides, that means reaching the top and bottom of the ear leaf. For insecticides, it means getting deep into the canopy and the undersides of the leaves – where the pests live. Those are difficult areas for aerial applicators to hit.
EXTENDED FIELD TRIAL DATA