Zeszyt: 2017, vol. 14 / II / 1
During flow of water from upstream to downstream in a controlled manner, the flow of water at high velocity and pressure, which occurs as a result of hydraulic jump is broken by energy dissipation structures in relief or accumulation structures. Otherwise, the flow of water with high velocity and pressure in the downstream section, where the stream passes from a flood regime to a river regime, will damage its own structure and surrounding environment. For this reason, it is necessary to design energy-dissipating structures at appropriate locations with appropriate sections so that large pressure and friction forces do not cause abrasion and erosion in flow chamber.In this study, flow characteristics such as pressure distribution, outlet flow, velocity distribution etc. of the water flowing from a dam infill located in Adrasan town of Antalya province was determined. Then, dam spillway was modelled in the computer environment with the actual measurements and analyzed according to Computational Fluid Dynamics method (CFD) using ANSYS-Fluent software. Finally, the actual measurements were compared with the simulation results. Additionally, measured data were compared with the downstream flow characteristic by defining to dam and spillway projecting software of General Directorate of State Hydraulic Works (pro-SHW).As a result, the ...
The usefulness of estimating hourly reference evapotranspiration for assessing the water requirements of plants over a 24 hour period was determined in the study. The values of hourly (ET0,h) and daily (ET0,d) evapotranspiration were calculated using the Penman-Monteith (PM) model. The daily ET0 was calculated automatically by the meteorological station, and the evapotranspiration values for individual hours were calculated using spreadsheet software. To verify the values of evapotranspiration calculated with these two approaches in relation to the actual water needs of grass, lysimetric measurements were performed. Additionally, substrate moisture content and temperature were measured using capacitance probes. The values of evapotranspiration estimated with the hourly PM model were higher than those determined with the daily model. An accuracy of the hourly model in relation to the data measured with a weighing lysimeter depended largely on the quality of the reproduction of meteorological parameters at the site of the crop. Observed underestimation of the actual daily evapotranspiration was presumably due to the use of air temperature values in the calculations (measured at a height of 2 m by the weather station). During strong solar radiation the air temperature was much lower than the temperature of the upper layer of the substrate ...
Spring frost in the blooming time can be a significant factor decreasing the fruit production and affects the cultivation profitability in the years with unfavourable weather conditions. In Poland, the fruit trees especially susceptible to damage are peach and apricot trees. Among the popular methods of protecting the trees against spring frost damage there are three kinds of treatment: sprinkling irrigation, fogging, smoking and using fans for mixing the layers of air. The costs of applying the particular methods differ, as well as their efficiency. The side effect of using them can be also orchard pollution. The experiment was conducted on selected peach tree cultivars, on two rootstocks. Two methods of spring frost protection were applied: sprinkling irrigation and fogging with the use of glycerin mixed with tap water in proportion 1:10. Sprinkling irrigation proved to be more effective, it protected 98% of blooms. Using the fogging device also brought a satisfying effect. The cultivars that were easily damaged by spring frost were 'Early Redhaven' and 'Cresthaven'. The greatest resistance to bloom damage was observed in the case of the 'Suncrest' and 'Saturn' trees. The yielding of the 'Inka' and 'Early Redhaven' trees protected by sprinkling irrigation was significantly better, ...
Information on the energy needs of agricultural production activities carried out in any region can be obtained in advance. Many methods are used for this purpose. One of them is a degree-hour method. Kumluca district of Antalya province where pepper cultivation is done intensively was chosen as a study area. The growers prefer autumn production of pepper plants inside the greenhouses in this region. Production starts in early October and last until June. The long-term (1960 - 2015) thermometer temperatures in the study area were obtained from the Turkish State Meteorological Service. In this study, by using only meteorological data, during each growing season (planting, flowering, pollination, fruit ripening and harvesting) were obtained degree-hour values for the pepper plant and evaluated with Student-t test. Regression coefficients were obtained by correlating heating and cooling degree-hour values with different temperature values which are recommended during the vegetative growing season for the pepper plant. Regression analysis was performed between obtaining heating and cooling degree-hour values (dependent variable) and annual mean heating and cooling degree hour values (independent variable) which are suggested basic temperature values. In conclusion, the regression coefficients were determined as 0.99 for out of greenhouse heating degree-hour and as 0.90-0.99 for ...
The aim of the study was to analyze the presence of mites (Acari), with special focus on indicator oribatid mites (Oribatida), in control pine wood chips and pine wood chips enriched with peat and lignite inoculated with forest litter and irrigated. The study was conducted in 2013 on microplots (1 x 1 m) located within a belt of trees in a nursery in Białe Błota. The experiments included the following variants: C - pine wood chips, Ec - pine wood chips inoculated with forest litter, Ec+Pe - pine wood chips enriched with deacidified high peat (20%) (pH 5.5-6.5) and inoculated with forest litter, Ec+Ca - pine wood chips enriched with granulated lignite (20%) (granule size 1-10 mm) inoculated with forest litter.The addition of forest litter caused an increase in total number of mites in the control pine wood chips and those enriched with peat. Mites belonging to Mesostigmata order prevailed in control chips and those enriched with forest litter and peat, while Oribatida were dominant mites in the other variants. Considering the results for the entire year, 20% addition of peat and lignite negatively affected the presence of oribatid mites, thus indicating a reduced biological activity of the substrates. The ...
The effect of deficit irrigation imposed in July-August period on shoot growth and flower formation in container grown rhododendron in commercial nursery were assessed. Plants were exposed to three irrigation regimes based on potential evapotranspiration rates (100% ET0 - well-watered control plants, 75% ET0 - moderate drought and 50% ET0 - severe drought). The values of evapotranspiration were calculated using the Penman-Monteith model. The degree of drought had significant effect on the plant growth and water status of plants. Severe drought inhibited secondary shoot elongation compared to less stressful regime but did not affect flower formation. ‘Catawbiense Boursault', ‘Nova Zembla' and ‘Pearce's American Beauty' plants exposed to severe drought were shorter, respectively by 39, 45 and 86% than well-irrigated plants and two of the three cultivars ‘Catawbiense Boursault' and ‘Pearce's American Beauty' produced fewer secondary branches (5.9 and 0.3) compared to control plants (9.2 and 1.7, respectively). Moderate drought did not affect plant growth but resulted in flower bud formation in ‘Nova Zembla' and ‘Pearce's American Beauty's cultivars. Estimated water consumption by rhododendrons throughout the whole growing season was reduced by 15% for moderate and 25% for severe drought compared to control, well-watered plants. The results have significant implications ...
The suitability of capacitance probes for measuring the actual variations in substrate water content in container-grown ornamental species (Lawson cypress) was examined. The probes were installed in the plant containers. Weighing measurement data on water loss was used to assess the actual changes in substrate water content (plant water use). In an additional test, an evaluation of temperature sensitivity of the capacitance probe was performed under laboratory conditions. The probe was placed in a container containing the growing medium (peat substrate) with a defined (stable) moisture content. The substrate temperature was modified and the changes in probe output were recorded. The experiment demonstrated the existence of the effect of temperature on the quality of soil moisture measurements conducted with the capacitance method. The accuracy of the results obtained from measurements with dielectric sensors in relation to the data obtained by means of weighing platforms depended largely on the temperature profile of the measured medium. It was demonstrated that temperature variations explained 99% of the observed differences in the results of moisture content measured with the capacitance method. Due to the fact that there is no possibility of developing universal factors (for different sensors and substrates) for correcting the influence of ...
In temperate zone, early freeze, particularly if preceded by a period of warm and wet weather, can severely injure many woody plants. The young plants are particularly sensitive to frost, especially those grown in containers. The timing and capacity of cold acclimation are modified by environmental cues. We examined whether regulated deficit irrigation (RDI) imposed in the fall affects cold acclimation of containerized Lawson cypress (Chamaecyparis lawsoniana)‘Columnaris' and Knaphill-Exbury azalea (Rhododendron) ‘Oxydol'. Three-year-old plants were grown in containers placed in the open field and were cultivated according to standard nursery practice. In the end of growing season (from 5th October to 2nd November 2015, half of the plants were expose to moderated water stress by ceasing irrigation and protecting them from the rain (RDI treatment). The volumetric water content of the growing medium gradually decreases in this time from 0.45 to 0.2 m3/m3. Irrigation of the second part of the plants were continued in October and water content was maintained at 0.45 m3/m3 (control treatment). Cold hardiness of stem tissues was assessed two times (2nd November and 7th December) in the laboratory using the ion-leakage test. Stem tissue were exposed to 6 test temperatures, ranging from +4 to -26˚C. Additionally, ...
The aim of the research conducted in the conditions of Lower Silesia in the years 2012-2016 was to evaluate the growth and yielding of young peach trees cultivated in ridges with drip irrigation. The experiment concerned the flat-fruit peach trees, cultivar Saturn on the Manchurian peach tree seedling, planted in the spring of 2012 in the spacing 4.0 x 1.5 m.In each year the shortage of rainfall was observed, as compared to the years 1997-2000. During the vegetation period, the deficiencies were from -7.3 mm up to - 221.7 mm. The insufficient amount of rainfall was accompanied by the rise of the mean air temperature in the vegetation period by 0.5 - 1.7oC. In the orchard, the drip irrigation in the form of stippling tape T-Tape TSX515-50-380 was applied, with the emitters every 50 cm and the expenditure of 3.8 l per metre in 1 hour. The humidity measurements were being taken from the beginning of May until the end of July with the use of Watermark probes, testing the sucking power of soil at the depth of 20 cm. The irrigation started when the water potential of soil was 30 kPa.During the 4 years, the total yield per hectare ...
An innovative technology of superabsorbent application in a form of agrotextile filled with polymer, called geocomposite, is a solution that allows preserving the beneficial effect of using superabsorbents with simultaneous reduction of their negative influence on soil environment. Research was carried out in 2012-2014 on one year old cuttings of Rosa 'White Meidiland' and Berberis thunbergii 'Green Carpet' in unheated foil tunnel at the Research Station belonging to the Department of Horticulture at Wrocław University of Environmental and Life Sciences. First factor was the use of geocomposite, while the second was fertilization with full (3 g) and half (1.5 g) dose of Osmocote Plus 3-4M and 3 g of YaraMila Complex fertilizer. The aim of this study was to assess the influence of geocomposite application with the use of fertilizers on selected biometric features and fresh weight of plants. Geocomposite had the positive influence on tested shoots and roots biometric features of Rosa ‘White Meidiland' and Berberis thunbergii 'Green Carpet', on the fresh weight of roots and total of both species, as well as on their root:shoot ratio. In both species there was a tendency to obtain the highest values with 1.5 g Osmocote fertilization. ...
To evaluate the economic efficiency of irrigation in corn cultivated for grain, production effects were used, which were obtained from studies conducted by researcher team from the Department of Land Reclamation and Agrometeorology at the Experiment Station of the UTP University of Science and Technology in Bydgoszcz in 2005-2016. The research covered the effect of irrigation on yielding of the crop. Economic efficiency calculations were made using the direct surplus increase calculation method. In each variant irrigation enhanced production effects. It was not always economically justified, however. The irrigation costs (for drip and sprinkler irrigation systems) per hectare were decreasing with an increase in acreage. Applying drip irrigation was economically unjustified in moist years and on average in the multi-year period. In the years with dry and average precipitation conditions the direct surplus was positive, except for irrigation of 1 ha. As for the sprinkler-irrigation system, a lack of economic efficiency was reported in moist years, whereas in dry and average years as well as on average in the multi-year period, except for 1 hectare acreage, corn sprinkler-irrigation was economically justified. ...
The aim of the research was to improve the germination parameters of red beet monogerm clusters using pre-sowing treatments. Red beet (Beta vulgaris L.) clusters of two monogerm breeding lines, AR79A and W411A, differed in the initial germination capacity, were studied. Five seed treatments including rubbing, leaching for 4, 8 and 24 hours, and soaking for 24 hours, were performed. Based on the germination test carried out at 15 and 20ºC, the germination traits, such as the mean germination time (MGT), coefficient of uniformity of germination (CUG), coefficient of velocity (COV), germination capacity (GC) and germination rate (GR), were measured. Compared to the control, treatments used in the study improved the most of measured germination features for both tested lines. The leaching of clusters for 24 hours yielded the best enhancement in most of the germination traits. The rubbing was the least effective technique in terms of improvement in the germination parameters. The germination of treated clusters at 15 and 20°C presented comparable, and better than the control, values of germination features. The interaction between treatment method and germination temperature showed that leaching of clusters for 24 hours and germination at 20°C was the technique that successfully influenced the majority ...
This paper presents data on daily precipitation totals from six meteorological stations and the climatic water balance for the stations located throughout Poland in 2011-2015. The following sequences of days without precipitation were distinguished: from 11 to 15 days, from 16 to 20 days, and of more than 20 days. The number of precipitation-free sequences during the growing season in 2011-2015 was highly variable. Over the studied period, there were from 1.0 rainless sequence in Wtelno to 2.4 such sequences in Gołębiów per one growing season. The most frequently occurring were sequences of 11-15 days, while those of 16-20 days were less frequent. In the years under analysis, all of the different sequences occurred most frequently in July, and the least frequently in April. The highest numbers of sequences without precipitation were recorded in the south-east of Poland (Zakalniki, Gołębiów). ...
