Little information is available concerning the utilization of soil moisture by sugar beets (Beta vulgaris) under dryland conditions in a semiarid environment. The influence of population (26,400 and 70,700 plants/ha) and N fertilizer (0, 56, 112, and 224 kg N/ha) on water use by sugar beets under such conditions was studied. The growing season was characterized by long periods with little precipitation, and extensive use was made of stored soil moisture to a depth of at least 183 cm. The higher population and N fertilizer treatments increased water use by approximately 9.5 and 3.5%, and yield of sucrose by approximately 20 and 15%, respectively. The leaf area index was increased percentage‐wise much more markedly by both treatments. During the growing season the greatest effect of increasing population on water use was most evident in the deepest depths from which moisture was being utilized. The sugar beets apparently utilized soil nitrate to at least 152 cm.