A field experiment was carried out during the winter seasons of 2018/19 and 2019/20 at Agricultural Experimental Farm, Faculty of Agricultural, Al-Azhar University, Assiut, Egypt (27o 12- 16.67" N latitude and 31o 09- 36.86" E longitude). The study aims to assess the effect of two furrow irrigation practices (conventional; CFI, and alternate; AFI), three rabbit manure application rates (R0: 0, R1: 6 and R2: 12 ton ha-1) and three potassium sulfate levels (KS0: control, KS1: 85 kg K2O ha-1, and KS2: recommended dose; 170 kg K2O ha-1) on potato yield and its macronutrient contents and on some water relations. The study aimed also to develop local potato crop coefficient (Kc) The experiment was laid out in split split plots design with three replicates. The main plots were allocated to furrow irrigation, the sub plots were assigned for rabbit manure and the sub sub-plots were assigned for potassium sulfate.

The obtained results indicated that, the CFI practice with R0KS0 realized the highest amount of both water consumptive use (WCU) and irrigation water applied (IWA) through both seasons, it was 5399.7 and 7523.4 m3 ha-1, respectively . While the lowest amount of WCU and IWA were obtained by AFI practices with R2KS2 through both seasons it was 4063.7 and 5455.8 m3 ha-1, respectively. The highest values of both irrigation and crop water productivity were attained by AFI with R2KS2 through both seasons it was 9.42 and 7.02 kg m-3, respectively. While the lowest values were obtained by CFI with R0KS0 through both seasons for the corresponding parameters it was 4.42 and 3.16 kg m-3, respectively. The crop coefficient (Kc) value started to increase at the beginning to reach its maximum value (Kc mid) at the time of near mature plant, it varied from: 0.63, 0.70, 1.03 and 0.98 for initial, development, mid and end season stages, respectively. The highest amount of saved water (28.23%) was attained by AFI practices with R2KS2 through both seasons compared to CFI with R0KS0. Generally, the potato tuber yields and N, P, K content were significantly influenced by furrow irrigation practices, as well as by adding rabbit manure and potassium sulfate, the highest yields were 37.87 and 38.35 ton ha-1 for first and second seasons, respectively under AFI. It might be concluded that practiced the alternate furrow as an irrigation system with R2KS2 achieved the highest potato tuber yield with good quality.