Water needs of bird cherry trees at the period over three years after reclamation in different regions of Poland

The purpose of the present study was to determine the water needs of bird cherry (Padus avium Mill.) over three years after planting on the reclaimed areas. The estimations were performed for the period of two months, including July and August, which are critical in terms of the amount of water available to the plants. The water requirements of bird cherry plants were calculated in the years 1981-2010 for five agro-climatic regions of Poland with the representative meteorological stations located in Olsztyn, Bydgoszcz, Warsaw, Wrocław and Krakow. The bird cherry water needs were determined using the plant coefficient method. The plant coefficients for bird cherry trees over three years after planting were adapted to the reference evapotranspiration that was calculated using the Blaney-Criddle’s formula, modified for Polish conditions by Żakowicz. The rainfall deficit with the probability of occurrence of average dry years (N50%), medium dry years (N25%) and very dry years (N10%) was determined according to the Ostromęcki’s method. On average, in the years 1981-2010, in July and August, the highest water needs of bird cherry trees, grown on the reclaimed areas over three years, were estimated in the centralnorth-west (271 mm) and central-east (270 mm) region of Poland. While, the lowest water requirements of bird cherry (240 mm) in the south-east region of the country was calculated. In August, the highest bird cherry water needs (121 mm) were estimated also in the central-north-west and central-east region of Poland, whereas the lowest water requirements (111 mm) occurred in the south-east region of the country. In each considered region of Poland, in the years 1981-2010, a visible increase in bird cherry water needs in the period of the highest water requirements, was noted. With the exception of the centralnorth-west region of the country, the temporal variability of bird cherry water needs was significant throughout Poland. [...]Vytauto Didžiojo universitetasŽemės ūkio akademij