Summary:

The aim of the research was an evaluation the impact of sprinkling irrigation, nitrogen fertilization as well as an interaction of the two factors on yield and malting quality of grain of two malting barley varieties‘Mauritia' and ‘Marthe'. A field experiment was conducted during the growing seasons in years 2010-2011 on sandy soil with dense subsoil in the Research Centre of University of Technology and Life Science - Mochełek nearby Bydgoszcz. This is an area in Poland of the highest average precipitation shortages and the needs of use the supplemental irrigation in terms of the climate criterion. On such type of soil, the irrigation had an interventionist role which is typical for the climatic conditions in Poland. It complemented periodic shortages of precipitation during the increased water needs of barley. Research hypothesis assumed that the use of irrigation in the technology of barley cultivation will increase and stabilize yields of grain and contribute to the acquisition of raw material that meets the criteria of brewing, regardless of the agricultural droughts occurring in a growing season. It was also assumed that, in terms of irrigation it would be possible to use higher doses of fertilizer than in conventional cultivation conducted under natural rainfall while the increased level of nitrogen fertilizer would increase yields without deteriorating the quality of grain destined for the brewing industry. The results of field experiments confirmed the hypothesis that the use of irrigation for malting barley production technology is a recommended procedure in terms of shaping indicators of production and quality. However, in agricultural practices, the possible use of irrigation in the cultivation of high quality malting barley varieties will depend primarily on the economic efficiency which would be shaped by the value of the yield (the price of a high quality material) as well as the infrastructure of a farm, mainly the availability of water resources for irrigation. In terms of yield useful for malting and the quality properties of grain, the optimal level of nitrogen fertilization of irrigated malting barley crops should be of 30 kg•ha-1. Increasing fertilizer up to level of 60 and 90 kg.ha-1 did not result in the increased grain weight, while definitely deteriorated its quality, whereby it contributed to the deterioration of the suitability the raw material for malting. Therefore, the second research hypothesis was negatively verified.