Many producers apply the N fertilizer to the cotton crop at or shortly after planting. However, the period of high N demand by the cotton crop does not start until the early bloom. Therefore, N fertilizer applied early in the season can be lost by leaching and denitrification before the period of high N demand. Synchronization of N fertilizer application and the period of high N demand will increase cotton N use efficiency. Replicated N rate field studies were conducted at multiple locations in 2006 to evaluate the cotton response to split application of N fertilizer and identify pre square soil N levels where no response to N application will likely occur.