Öz This study investigated the effect of nitrogen (N) fertigation frequency and different amounts of irrigation water on drip-irrigated silage corn. Experiments were conducted in the Southeastern Anatolia region of Turkey in 2011 and 2012. A split-plot experimental design was applied. The main plots contained four different rates of evaporation from Class A pan (Ep): I1, 50 %, I2, 75 %, I3, 100 %, and I4, 125 %. Sub-plots were designed with different frequencies of N fertigation as follows: N1: application of two-fifths of the total N when the plant height became about 50-60 cm, and the last two-fifths of it when the plants entered the stage of tasseling, N2: application of N applied at each 2 irrigation cycles for 10 days, and N3: application of N applied at each irrigation cycle for 5 days. One-fifth of the total N was applied to the soil at sowing in all treatment regimes. The dry matter biomass (DM) of 30 t ha-1 and total crude protein yield of 2.0 t ha-1 were obtained with N application of equal amounts at each irrigation cycle (5 days) and irrigation water consisting of 100 % cumulative evaporation from Class A pan (Ep) for an optimum and appropriate treatment. Nitrogen use efficiency (NUE) and irrigation water use efficiency (IWUE) were 107.7 kg DM ha-1 N and 58.0 kg ha-1 mm-1 (5.8 kg m-3), respectively. The requirement of the average value of irrigation water and the optimum wetted area ratio for drip-irrigated silage corn were 447 mm and 0.65, respectively.Key words: dry matter, fertigation, nitrogen use efficiency, protein, silage corn