The aim of the study was to analyze and evaluate the occurrence of atmospheric drought during summer half-year in Wroclaw - Swojec over the 50 years 1961÷2010. For that purpose daily values of precipitation totals were used, measured at the Agro- and Hydrometeorology Observatory that belongs to the Wrocław University of Environmental and Life Sciences. Analyses were performed for particular months from May to October for 50-year period 1961÷2010. The assessment of atmospheric drought occurrence was based on the string of days without precipitation, using the criterion proposed by Schmuck for their designation. The analyzes carried out showed a decreasing tendency of the number of strings of days without precipitation lasting 9 days and more during the 50-year period 1961÷2010, but not statistically significant. This trend has stabilized during a 30-year period 1961÷1990. Mostly drought occurred in October and the least frequently in July. Longer periods without precipitation (moderate drought ) were characterized by more frequent occurrence in late summer (August ) and in September and October. In contrast, intensive drought on that area occurred sporadically and only in the period of September - October. The obtained results were consistent with the results of other authors obtained for Wroclaw for ...
The aim of the study was to evaluate the growth dynamic of Scots pine on the post arable ground under mulch in the third year of cultivation. Planting were carried out on the basis of post arable ground located in the Agro and Hydrometeorology Observatory of the University of Life Sciences in Wrocław. Scots pine plants in the third year of cultivation increased in height from 68.8 cm to 102.5 cm, ie. by 33.7 cm about 49%. The growth rate of pine was the highest in the first part of the growing season (until June 10), when the plant height increased by 30 cm, accounting for about 90% of the total, the annual increment in height. The second biometric parameters studied - the diameter of the trunk - increased in the third year of growing pine from 28.0 mm to 39.9 mm (about 11. 9 mm, ie. about 42%). The growth rate as a trunk diameter was different from that recorded in the case of plant height, because in the first part of the growing pine, wherein the largest increase its height, stem diameter increased by only 29% of the annual growth (ie. about 3.4 mm). ...
The paper presents an application to calculate the daily reference evapotranspiration values (ETo), understood as the amount of evaporation from the lawn surface fully developed, growing on the soil, which provides optimal growth conditions. The presented application allows to determine the ETo value for any location for given geographic coordinates and location above sea level on the basis of daily values of air temperature, saturation deficit, wind speed and relative sunshine. As the input data there are also variables such as psychometric constant dependent on the location above sea level and atmospheric pressure, the maximum vapor pressure and the slope vapor pressure deficit dependent on temperature, extraterrestrial radiation dependent on sequent day number of the year, which in Evapo application are determined automatically based on given geographical information. The application allows to analyze evapotranspiration variability during particular years and months. Basing on 30 years of meteorological data the values of evapotranspiration for the Vancouver and Wrocław - Swojec was calculated and exemplary analysis was performed using the presented application. ...
The aim of the study was to estimate the variability of biometric parameters in the second year of cultivation of Scots pine on the post arable ground. Planting were carried out on the basis of post arable ground located in the Faculty Agro and Hydrometeorology Observatory of the Wrocław University of Environmental and Life Sciences. Scots pine plants in the second year of cultivation increased in height from 43.1 cm to 53.39 cm, 10,29 cm, i.e. 24 % ie. The growth rate of pine was the highest in the first part of the growing season (until June 14), when the plant height increased by 7.69 cm, accounting for about 75% of the total, the annual increment in height. The second biometric parameters studied - the diameter of the trunk - increased in the second year of growing pine from 13.16 mm to 23.36 mm (by 10. 2 mm, ie. about 77 %). ...
The aim of the study was to compare the water requirements and the precipitation deficiencies during cultivation of asparagus in the period from June to August in the regions of Bydgoszcz and Wroclaw. The water needs were calculated using the plant coefficient. The reference evapotranspiration was measured by Grabarczyk's method (1976). The coefficients kc, determined for the Polish conditions by Rolbiecki (2013), were used to estimate the water requirements considered as the crop evapotranspiration. In the studied period (from June to August, 1996-2015), higher water requirements of asparagus were noted in the Wroclaw region (366.1 mm) than in the Bydgoszcz region (288.5 mm). The monthly water needs in June, July and August were 69.8 mm, 128.8 mm and 167.5 mm, respectively, in the Wroclaw region, and 55.5 mm, 98.5 mm and 134.5 mm, respectively, in the Bydgoszcz region. In July, the tendency to increase the water requirements in both observed regions was noted. The monthly crop evapotranspiration in July rose in each decade by 12.3 mm in the Bydgoszcz region and by 21.2 mm in the Wroclaw region. In the 20-year study, the rainfall deficit in June and July during 11-13 years was noted. In August, the precipitation deficiencies were ...
