Effect of nitrogen and irrigation management on potato (Solanum tuberosum L.) yields

Nitrogen is the major element that limits potato growth and yield under dry and saturated water stress condition. This study evaluated the effect of nitrogen and irrigation management on potato (Solanum tuberosum L.) yields. Potato has a relatively shallow root system with most roots located in the top 50 cm of soil and an application of fertilizer under and/or 5-10 cm of potato root zone may not be efficient. The highest amount of N is needed for the period of tuber bulking that is the stage at which about 58–70% of the total N is taken up. Supplemental irrigation of 55 mm could increase potato yield up to 50.8%. Application of irrigation water beyond the limit may result in nitrogen losses and hence low nitrogen use efficiency (NUE). Based on this fundamental knowledge, a potato farmer may choose the correct type, time and amount of fertilizer to be applied. The supplementary irrigation is also recommended for farmer experiencing drought effects to increase their productivity. Key words: Irrigation, Nitrogen, Nitrogen Use Efficiency, Solanum potato, yield