Influence of Deficit Irrigation and Nitrogen Fertilization on Potato Yield, Water Productivity and Net Profit

Abstract

Potato is described as a sensitive crop to short periods of irrigation deficit and Nitrogen deficiency.  Farmers usually use excessive amounts of irrigation water and fertilizers to obtain higher yields. Recently, there is a shortage of water resources and therefore it is fundamentally important to employ better irrigation and fertilization management of such crops. A field experiment was undertaken to assess the effects of irrigation regime and Nitrogen fertilization on potato tuber yield, Chlorophyll content and irrigation water productivity of potato crop. Four levels of applied water 1.25, 1.00, 0.75 and 0.50 of the crop evapotranspiration (ET_c) were examined with three amounts of Nitrogen (N) 50, 125, and 200 kg ha^-1.  The results clearly demonstrated a significant influence of both factors on potato yield. The highest potato yield of 29.3 Mg ha^-1 was obtained with the treatment of 1.25 ET_c and 200 kg N ha^-1. Water productivity was conversely proportion with increasing amount of applied water since the highest average record of 27.2 kg m^-3 obtained with lowest amount of applied water. The results further showed an inversely proportional between irrigation regime and water productivity which was reflected on the total profits.  Consequently, the results suggest that potato can be grown in arid and semi-arid environments with acceptable potato yield and quality while saving water and using Nitrogen fertilization more efficiently.