Summary:

The purpose of the study conducted in the years 2005–2006 in Kruszyn Krajeński near Bydgoszcz was determining the influence of irrigation and nitrogen fertilization on morphological features of root systems as well as overground parts of millet cultivable varietes Gierczyckie and Jagna including the structure of grain yield. The plants were cultivated on a very light soil. The research shown that irri-gation significantly determined various values of morphological features of over- and undeground parts in each tested varitety of millet, where Jagna variety re-acted better on this experiment factor than Gierczyckie variety. In each variety the mass of overground parts of millet as well as the mass of grain increased more in-tensive in relation to the mass of roots and P2 (ratio of the overground-part mass and roots mass). Each variety used in the experiment reacted positive on nitrogen fertilisation, where, with no irrigation, Gierczyckie variety more effectively use higher nitrogen frtilisation doses (80-120 kg•ha^-1), whereas Jagna variety lower doses (40-80 kg•ha^-1). Irrigation increases the effectiveness of nitrogen fertilisa-tion for Gierczyckie variety, when nitrogen fertilisation dose reach 40-80 kg•ha^-1 and for Jagna variety 40 kg•ha^-1.