Objective: To reveal how water affects fertilizer is important to make decision to regulate and control water and fertilizer use. Method: The paper described temporal-spatial character of soil N extracted by alkaline affected by different irrigation water usage in Awati County, Xinjiang. Result: Irrigation resulted in change of soil N content in depth from 0 cm to 100 cm obviously, especially from 0 cm to 40 cm; generally the more water irrigated, the more nitrogen dissolved and moved down. Conclusion: One reason that water promoted fertilizer use efficiency was to enlarge distribution area of nitrogen in soil profile, then more cotton roots could adsorb nutrients.
