Anhydrous ammonia (NH3) was applied at the rate of 67 kg/ha on 20 July and 8 September the summer after harvest and 15 May, 30 May, 15 June, 30 June, 15 July, 30 July, and 15 August the following summer during two 14‐month fallow periods on Aridic Haplustoll and Torripsamment soils. The study was conducted to determine the ammonia application date during the 14‐month fallow period which produced the soil water‐soil NO3‐N distribution in the soil resulting in the maximum protein levels and grain yields of winter wheat (Triticum aestivum L.). Soil NO3‐N and soil water contents were determined to a 180 cm depth on each application date and at wheat seeding (15 September). In the Aridic Haplustoll soil, NH3 had to be applied in the summer after harvest (over 1 year before wheat seeding) for maximum NO3‐N accumulation in the soil between 60 and 120 cm which produced the highest protein grain (14.5%) and the highest yield (3,269 kg/ha). In the Torripsamment, NH3 applications between 15 May and 30 June the year of wheat planting produced highest protein grain (13.4%) and highest grain yields (2,688 kg/ha). However the optimum NH3 application date to produce the desired NO3‐N accumulation in the 60 to 120 or 150 cm soil depths in the Torripsamment was not determined in this study.