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Abstract. Increasing water demands and prolonged periods of drought are forcing many farmers in Nevada to grow alfalfa without meeting its full irrigation demands, a practice known as deficit irrigation. Deficit irrigation (DI) is a strategy that can help increase crop water productivity (CWP)—defined as the yield obtained per unit of water consumed by the crop—but it can also lead to water stress conditions that negatively impact yield. The objective of this study was to assess the effects of deficit irrigation on the alfalfa (Medicago sativa L.) yield and CWP of two alfalfa varieties (Ladak II and Stratica). The experiment was conducted at the Valley Road Field Lab in Reno, Nevada, and was initiated during the Fall 2020. Three irrigation treatments were applied to each variety: 100, 80, and 60% of replenishment of soil water depletion to field capacity. Irrigation requirements were calculated using hourly volumetric water content readings obtained from a network of soil water sensors connected to the Internet of Things. Irrigation amounts were applied using a drip irrigation system. There were significant differences among irrigation treatments on alfalfa yield (p < 0.05), but alfalfa variety did not affect yield (p > 0.05). CWP ranged from 0.11 to 0.13 Mg ha^-1 cm^-1, but in general, there were no significant differences among treatments.