Optimizing nitrogen fertilizer management can reduce nitrous oxide (N 2 O) emissions. This study tested if split applying enhanced efficiency fertilizers (EEFs) resulted in lower N 2 O emissions than applying equivalent rates of urea at planting. In semiarid southern Alberta, field trials were conducted during three years (planting to harvest) in rainfed winter wheat crops. Annual fertilizer rates ranged from 146 to 176 kg N h...