The experiment was conducted was in the years 2005-2007 on the very light soil in Kruszyn Krajeński near Bydgoszcz. The influence of sprinkler irrigation and the differentiated nitrogen fertilization on yields of early potato cv. ‘Dorota' was studied. This experiment was established as a two-factorial trial. The first-row factor was sprinkling irrigation applied in two variants: W0 - without irrigation (control), W1 - sprinkling irrigation. The second row factor - differentiated nitrogen fertilization, was used in the four following variants (doses): N0 = 0 kg N•ha-1, N1 = 40 kg N•ha-1, N2 = 80 kg N•ha-1, N3 = 120 kg N•ha-1. Potatoes were fertilized with the full dose of manure, the fertilization with P and K was uniform on all the plots, and it was applied in relation to the soil fertility. The mean yield harvested on control plots (without irrigation) amounted on average 14,41 t•ha-1. Smaller yields, in range 8,75-11,83 t•ha-1, were noted in the first two years of study which were characterized by lower rainfall (161-230 mm), higher yields (22,66 t•ha-1) - in year 2007 that was characterized by the highest rainfall (323 mm) in the vegetation period of the potatoes. The use of irrigation significantly increased ...
