We designed this study to demonstrate the differences in nitrogen rates and yields with different urea application times.

Spring timing gave the best return to nitrogen dollars spent. Fall had the worst return and lowest yield. 2011 weather patterns favored spring application. Conditions resulted in especially high potential nitrogen losses during the winter and early spring.

Take Home Lessons:

• Spring nitrogen application resulted in the highest yields.
• Spring timing delivered the most efficient in nitrogen use.
• Fall timing afforded lower maximum economic rate of nitrogen (MERN) due to N losses reducing efficiency
• Fall application returned lowest yield
• Split application timing (1/2 in fall and 1/2 in spring) yielded better than fall application, but not as well as spring application.

Resources:

• Harms Corn After Soybeans NUE Timing.