A field experiment was conducted at Nubaria Agricultural Research Station during 2016/2017 and 2017/2018 to study the effect of irrigation regimes under saline calcareous soil on fresh and dry yields, quality, water requirements and productivity. Four irrigation regimes with amount of water equals potential evapotranspiration were used as irrigation with amount of water equal potential evapotranspiration (ETp) plus 10%, 20%, 30% and/or 40% as leaching requirements (LR). Average of calcareous soil salinity treatments were S₁ equal 2 dSm^-1, S₂ equal 6 dSm^-1 and S₃ equal 10 dSm^-1. Results indicated that there were significant effects among irrigation and soil salinity treatments on fresh and dry alfalfa yields through the combination of two years. The highest values of fresh and dry yields were 217.736 and 49.861 ton/ha, respectively that was obtained by I₁S₁ interaction, while the lowest values were 140.0 and 35.91 ton/ha was obtained by I₄S₂ interaction. Fresh and dry yields were decreased by 28.4 and 18.13% at I₁S₂ and by 14.6 and 13.19% at I₁S₃, respectively compared with that obtained by I₁S₁. Results of I₃S₃ and I₄S₃ were given the highest values of N and CP percentages. The water requirements values for alfalfa were 126.0, 135.2, 144.3 and 153.9 cm in the first year, while in the second year they were 128.8, 140.2, 152.0 and 163.8 cm for irrigation treatments, respectively. Also, the highest values of the productivity of irrigation water (PIW) were 8.93 and 8.17 kg/m³ water in 1^st and 2^nd years, which was I₁S₁.