Summary:

A field experiment was conducted during the growing season 2010 on sandy soil in Mochełek near Bydgoszcz. The effects of irrigation and the four variants of nitrogen fertilization on yield and quality of grain from brewing barley varieties 'Mauritia' and 'Martha' were inwestigated. Growing season of barley in terms of total rainfall belonged to the wet, however, was marked by an extremely uneven distribution of rainfall in different decades. During the period of tillering and ripening stage of barley rainfall amounted to only 16.3 mm, which resulted in the need for irrigation of plants. A total of five doses of 105 mm of water was used.
It was found that yields of barley grain ranged from 3.05 kg.ha-1 to
6.34 kg.ha-1, depending on the variety, irrigation and nitrogen fertilization variant. Regardless of the factors used, higher average yields of 31% was characterized by a variety of 'Martha'. The average increase in grain yield due to application of
irrigation was 37.3%. This indicates the high desirability of introducing this treatment to the malting barley production technologies as a factor which
increases the amount of grain yield in growing seasons characterized by the
occurrence of atmospheric and agricultural dry spells in the period of increased demand for water plants. Plant response to fertilization and its increasing doses depend on water conditions, varying as a result of irrigation. In conditions without irrigation, there was no significant difference in the level of yield of 'Mauritia' and substantially reduce the amount of yield of 'Martha' under the influence of the
application of increased doses of nitrogen. On irrigated plots yields of fertilized barley was significantly higher than those grown without fertilization. However, increasing the nitrogen dose from 30 to 60-90 kg.ha-1, did not result in significant increases in yields. Preliminary assessment of the suitability of grain for malting showed that the quality of raw material have been improved under the influence of irrigation and clearly deteriorated as a result of nitrogen fertilization, especially in an amount of 60-90 kg.ha-1. Grains derived from irrigated but not fertilized plots had the highest value for malting.