The field experiment was carried out in the years 2001–2003 at Kruszyn Krajenski near Bydgoszcz on very light soil characterized by limited water capacity. The aim of the study was to determine the influence of sprinkler irrigation and nitrogen dose on the yield, chemical
composition and storage value of potatoes cv. ‘Mors’. Irrigation significantly increased potato yields. A higher nitrogen dose did not significantly affect the amount of yield and its chemical composition. The storage of potatoes at storehouse six months significantly decreased the content of dry matter, starch and vitamin C in potato tubers.