Two soil profiles at Kruszyn Krajeński near Bydgoszcz were studied at the paper. Characteristic of soils and their water properties were determined. Air temperature (t) values and rainfall amounts (P) in particular months of vegetation period (April–September) in 1997–2006 for the investigated area were given. The vegetation period was characterized by mean air temperature 14,4 °C, ranging in particular years from 13,4 to 15,2 °C. Rainfall total during the vegetation period amounted on average 283,4 mm, ranging from 177,5 to 377 mm. Potential evapotranspiration (Etp) amounts were also determined using Grabarczyk’s formula. Irrigation requirements under the considered soil-climatic conditions were determined according to the following Drupka’s proposal: rainfall total (P) in the vegetation period as well as potential evapotranspiration (Etp) and difference Etp – P. Irrigation is needed when rainfall is lower than 370 mm, Etp is higher than 515 mm, and difference Etp – P is higher than 150 mm. On the base of rainfall amounts in vegetation period it can be stated that in years 1997-2006 irrigation requirements have been occurred in 8 seasons, and in two remaining years irrigation also could be needed because rainfall amounts were slightly higher from 370 mm (only by 4 and 7 ...
The study was carried out in order to determine the frequency of droughts in the period of increased water needs in potato, and to assess the needs and expected productive effects of the plants grown under irrigation on the basis of temporal variation of the standardized precipitation index SPI in the Kujawsko-Pomorskie district. Rainfall data were derived from standard measurements of atmospheric precipitation in between 1 July and 31 August in the multi-annual period 1981-2010.These data were obtained from the branches of COBORU in Chrząstowo, Głębokie and Głodowo, and the University of Technology and Life Sciences Research Centre in Mochełek. The results of carried research showed that the frequency of occurrence of dry spell during the period of increased needs for water of potato amounted to 26.7-40.0% in the region, depending on the locality. Strong droughts occurred in the year 1983, 1989, 1992 and 1994, moderate drought in 2005 and weak droughts in 1982, 1984 and 1999. Great irrigation needs of potato which corresponded to periods of strong and moderate droughts (SPI ≤ -1.0) have been identified in 5 years of the 30 years examined. The expected increase in the yield of potato tubers grown on light soils under irrigation ...
The study was carried out in order to determine the frequency of droughts in the period of increased water needs of corn cultivated for grain in the region of Kujawsko-Pomorskie based on temporal variation of the standardized precipitation index SPI. Also were assessed the needs and expected productive effects of the plants grown under irrigation by a significant correlation between increases of yields of grain and the amount of rainfall. Rainfall data were derived from standard measurements of atmospheric precipitation during a period from 1 July and 31 August in the multi-annual period 1981-2010. These data were obtained from the branches of the Research Centre for Cultivar Testing (COBORU) in Chrząstowo, Głębokie and Głodowo, and the University of Technology and Life Sciences Research Centre in Mochełek. The results of carried research showed that the frequency of occurrence of dry spell during the period of increased needs for water of corn amounted to 26.7-40.0% in the region depended on the locality. Strong droughts occurred in the year 1983, 1989, 1992 and 1994, moderate drought in 2005 and weak droughts in 1982, 1984 and 1999. Great irrigation needs of corn which corresponded to periods of strong and moderate droughts (SPI ...
