Summary:

The paper presents results of a field experiment with maize varietas ‘Cedro’ (FAO230) irrigated on a light soil, carried out in years 2000-2008 in Mochełek (near Bydgoszcz. A combination of 90 and 150 kg of nitrogen per hec-tar was applied. Water was supplied by a drip irrigation system using the NAAN emitters. The layout of drip laterals placed in beetwen plants’ rows provided a moisture to the soil in a root zone. In the years of the study an average dose of water of 112 mm was used for irrigation (28 mm in June, 49 mm in July, 28 mm in August and 7 mm in September), but in separate seasons the dose varried from 25 mm (year 2007) to 215 mm (year 2008). Irrigation have increased the yield of corn from 5,62 t.ha-1 to 8,53 t.ha-1, which is 2,91 t.ha-1(52%). The increase of the yield of corn in separate years varied from 0,46 t.ha-1 (year 2000) and 0,60 t.ha-1 (in a cold year 2004) to 8,47 t.ha-1(in year 2006 when the art temperature in July was very high) and 6,26 t.ha-1(in year 2008 when was a rainfall shortage in months V-VII). The results of the studies have shown that the effects of the suple-mentary irrigation have subordinated from the rainfall in July. The lowest was the rainfall in the month , the highest was the corn yield increase. Also the nitro-gen fertilization have influenced positively the effects of the yield, but in the com-parison with the irrigation effects, the increase was less and equalled of 0,25 t.ha-1. Both elements, water and nitrogen have influenced the constituents of yield but in a different way. Irrigation have increased the quota of corncobs in the total yield, the quota of corn in a cob and quality of corn, but slightly decreased a quantity of protein. The highest dose of nitrogen (150 kg.ha-1) has significantly increased the DM grain of maize and has slightly increased quantity of protein. Other constituents of yield i.e. a moisture of corn haven been influenced by the elements applied.