Nitrogen availability near flowering time and during grain fill is one of the most important differences in final yields.
Leaching and wash off of surface applied N, on wetter or compacted soils and in continuous corn situations have led to some later planted fields showing yellowing and stunting. Side dressing of small amounts of N could lead to yield increases, but it may take a while to get the active roots to reach the N.
Foliar feeding may be helpful to get the plants actively growing, so they can reach the available N. This is due partially to the fact that some surface Nitrogen was lost and partially due to the fact that roots stayed shallow due to a lack of oxygen during the cold period and now may be suffering from lack of moisture in the surface root zone.
Early planted corn has a deeper root system and more completely explored the N in the deeper soil profile.
Since Nitrogen is so important to your corn crop, the use of the Corn Nitrogen Rate Calculator Web tool will help guide you toward maximum profitability as the price of corn and the price of Nitrogen vary, but it only works if the Nitrogen is not lost before the plant gets to it.
Anytime you lay out cash for a hope of future return risk is involved. Manage that risk well by using a tool like the ISU extension Ag Decision Maker:
This is a great tool to use with your own costs and to help you put together a marketing plan for the crops or animals you manage, so you remain a profitable and sustainable farming operation. There are many input costs which you can control and the use of these tools emphasizes the need for a good marketing plan that is proactive rather than reactive. The people who had a marketing plan and sold or protected the price in June of 2016 were well rewarded last year, so preparing a marketing plan which will allow you to react to weather concerns this Summer may be a good move to be profitable in 2017.This is a critical year to have a plan that covers your variable production costs, since there is a lot of downside risk, especially for soybeans.