Streszczenie:

The aim of the research was an evaluation of the frequency and intensity of agricultural droughts and their effects in the province of Kujawsko-Pomorskie as well as to indicate ways of increasing productivity in such drought periods by applying irrigation. It was found that the drought periods around Bydgoszcz occurred in 17 vegetation seasons out of 30 analysed. They were differentiated by intensity and duration but were also characterized by high irregularity of their occurrence. In the past 30-year period, droughts were especially intensified in the years 1989-1995. In the years 2001-2005 droughts were rare (36%), as compared with the previous 15-year period of 1986-2000 (64%). Crop production of some selected agricultural cultivations in the province of Kujawsko-Pomorskie depended to a large extent on the degree of precipitation shortages in the periods of intensified water demand. The best correlations and determination coefficients exceeding 80% concerned maize cultivations. The occurrence of droughts, expressed by the degree of atmospheric precipitation shortages in June and July, led to a decrease in grain crops in the province by 13%, on average. In the extremely dry year of 2006, a decrease by 27%, in relation to average crops, was observed. Active methods of minimizing effects of agricultural droughts are connected mainly with the development of irrigation systems. In the experiments conducted in the years 2006-2016, it was shown that the application of irrigation of barley and maize in the drought periods not only prevented 40-45% decrease in crops but also provided higher cropping level (by 33-40%) than the one obtained on average without irrigation.