Figure 1.

Effect of different nitrogen (N) rates and application time on spring wheat grain yield in Pondera (a), Chouteau (b), and Teton (c) in two years. Treatments were designated in the format x:y, where x and y are the fertilizer N rates in kg N ha⁻¹ applied at planting and at flowering, respectively. Bars within the same year followed by the same letter are not significantly different (p > 0.05) based on a Duncan’s multiple range test.