Lack of water causes non-uniform development of plants during their growing season or even their drying-up. Nitrogen is one of the most important nutrients in the nutrition of higher organisms as well as microbes. Evaluation of the nitrogen nutrition status of plants and determining optimum doses of this element has a significant effect with regard to the economic aspect of production and necessity of protecting agricultural environment against nitrogen pollution. Two-factorial field experiment was carried out in the years 2007-2009 on soil of bonitation class IVa and IVb, and according to agricultural usefulness: complex 4 (very good rye complex) and 5 (good rye complex). The aim of the research was evaluation of the effect of sprinkling irrigation and diversified nitrogen fertilization (0, 80, 160 and 240 kg·ha^-1 N) on chosen elements of the yield structure and on variation of SPAD index in maize leaves (cultivar Clarica, FAO 280). A considerable variation in weather conditions was observed within the years of research. The driest, and at the same time the warmest was 2008, when both in late April as well as in May and June, the amount of rainfall was small. It was observed that the amount of rainfall in May has a significant effect on the maize yield, while sprinkling irrigation applied in June and July reduced the negative effect of drought occurring in late spring. Interaction of the experimental factors indicated that the highest grain yield was obtained after application of 80 kg·ha^-1 N with sprinkling irrigation. However, further increase of nitrogen fertilization dose did not result in any significant increase in the yield of maize grain. The value of SPAD index determined at the stage of flowering (BBCH 67) as well as at the milk stage (BBCH 75) was the highest with nitrogen fertilization of 240 kg·ha^-1. Application of sprinkling irrigation significantly increased values of SPAD readings independently of the level of nitrogen fertilization.

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