Was this ground no-till? How was the fertilizer applied? 

A lot of the corn that is washed out will likely die. Best way would be to drive the whole field and plant just the washed area putting corn back in same spot, this will help finish off the washed out corn. Plant a shorter maturity and hopefully harvest at the same time.

On our soils with nitrogen applied as NH3 with a striptiller and the strips washed out from a single flood lasting just 3 days, we have raised good corn without applying more fertilizer.  In another year with 6 floods it was obvious that the corn was short on nitrogen.