In potato cropping systems, nitrogen and water availability are essential factors for production. In this regard, water and nitrogen fertilizers management are considered a challenge in potato production. Therefore, this study was aimed to explore the effect of N source and rate in collaboration with different irrigation water regime on the vegetative growth, yield, and quality of potato.
To achieve this objective, a pot experiment was conducted during season 2020 at Soil and Water Research Department, Nuclear Research Center, Atomic Energy Authority, Inshas, Egypt. Experimental treatments consist of two drip irrigation water regimes (100 and 80% ETc), two N fertilizer sources (urea, and ammonium nitrate), which applied at three N fertilizer rates (120, 100, and 80%) of the recommended dose.
Significant increment in vegetative growth, yield, and quality of potato were detected under 100% ETc. Comparison between fertilizer sources reflected the superiority of ammonium nitrate which induced the highest values in all measured parameters, while the N rate of 120% achieved the highest values followed by 100%, then 80%. Regarding the interaction effect among irrigation levels, N sources and rates revealed that, the 100% ETc with the addition of ammonium nitrate at the rate of 120% gave the highest significant values of vegetative growth traits (plant height, number of leaves, vegetation fresh weight). Similarly, the highest yield and best tuber quality parameters (tuber number, yield/plant, N, proteins, carbohydrates, and starch content were induced by the same treatment of 120% ammonium nitrate rate in combination with 100% ETc.