Irrigation needs of orchard plants in Poland are presented in the work using the formula N = P – Po (mm), where: N – water needs (mm) in a given pe-riod, P – actual rainfall (mm) in a given period, Po – optimum rainfall (water needs of plants). Optimum rainfall amounts according to modified schedule of Press [1963] for three ranges of air temperature in the particular months of the vegetation period were taken into consideration. Needs N were determined for 27 chosen meteorological stations, for five fruit trees' basic species as well as strawberries. The higher water needs for fruit trees were determined in central belt of Poland with north region of Szczecin as well as regions of Poznań, Płock and Słubice. These needs in the vegetation period with high temperatures ranged from 160 to 190 mm for plum trees, 140–171 mm for apple trees, 50–81 mm for pear trees as well as 39–73 mm for sweet and sour cherries. Advantageous mois-ture conditions were determined in both extreme belts of country, but also here irrigation needs were occurred in case of plum-trees and apple-trees. The highest rainfall deficits were detected in regions ...
In this studies, a plant water needs index was defined as an amount of rainfall, in the period of plant increasing water demands, which didn't increase a yield of an irrigated plants. Such defined optimal rainfall was calculated on the basis of results of long-term field experiments carried out on two kinds of soil in a region of Bydgoszcz. Irrigation needs understood as rainfall insufficiency in the period of plant increasing water demands, were calculated as a difference be-tween optimal and actual rainfall. Homogeneous rainfall data from years 1971-2005 in Mochełek (placed near Bydgoszcz) were used. Calculations of irrigation needs were made in the period of increasing water demands of the followed plants: spring cereals, medium-early potato and maize cultivated for grain. All of them were grown on two kinds of soil: a very light soil of permeable subsoil and a light soil of compact subsoil. Obtained results enabled to classify the evaluated irrigation needs. The criterions were: a number of essential individual water doses and a quantity of forecasted productive effects of the irrigated plants. Re-sults of the studies show that the irrigation needs calculated on a very light soil in the region of Bydgoszcz occurred in 87,7-97,1% (it ...
The work was carried out in order to determine the frequency of droughts in the period of increased water needs of spring cereals. In addition, based on the time variation of the standardized precipitation index SPI assessed the needs and the expected production results of the plants irrigated in the Kujawsko-Pomorskie region. Data consisted of the results of standard measurements of rainfall from 1 May to 30 June in the period 1981-2010. Rainfall data were obtained from the branches COBORU in Chrząstowo, Głębokie and Głodowo and also from the Research Station of University and Technology and Life Science in Mochełek. Based on the results of the study, it was found that, during the period of high demand for water of spring cereals, the frequency of drought conditions in the region accounted of 23,3-30,0%, depending on the locality. Extreme droughts occurred in years 2000 and 2008, strong in 1983, moderate in 1989 and weak in 1992, 2003 and 2006. Among the analyzed 30 years, in 4 years were identified very high- and high-level requirements of irrigation in spring cereals corresponding to periods of extreme, strong and moderate droughts (SPI ≤ -1.0). The expected increase in grain yield of spring cereals ...
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 ...
