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Drivers of soil moisture trends in the Czech Republic between 1961 and 2012
Trnka, M. ; Brázdil, R. ; Balek, J. ; Semerádová, D. ; Hlavinka, P. ; Možný, M. ; Štěpánek, P. ; Dobrovolný, P. ; Zahradníček, P. ; Dubrovský, Martin ; Eitzinger, J. ; Fuchs, B. ; Svoboda, M. ; Hayes, M. ; Žalud, Z.
Soil moisture dynamics and their temporal trends in the Czech Republic are forced by various drivers. Our analysis of temporal trends indicates that shifts in drought severity between 1961 and 2012 and especially in the April, May, and June period, which displayed such results as a 50% increase in drought probability during 1961–1980 in comparison to 2001–2012. We found that increased global radiation and air temperature together with decreased relative humidity (all statistically significant at p < 0.05) led to increases in the reference evapotranspiration in all months of the growing season; this trend was particularly evident in April, May, and August, when more than 80% of the territory displayed an increased demand for soil water. These changes, in combination with the earlier end of snow cover and the earlier start of the growing season (up to 20 days in some regions), led to increased actual evapotranspiration at the start of the growing season that tended to deplete the soil moisture earlier, leaving the soil more exposed to the impacts of rainfall variability. These results support concerns related to the potentially increased severity of drought events in Central Europe. The reported trend patterns are of particular importance with respect to expected climate change, given the robustness and consistency of the trends shown and the fact that they can be aligned with the existing climate model projections. Introduction
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Assessing the impact of drought stress on winter wheat canopy by hermes crop growth model
Wimmerová, Markéta ; Pohanková, Eva ; Kersebaum, K. C. ; Trnka, Miroslav ; Žalud, Zdeněk ; Hlavinka, Petr
The main aim of this study was evaluate a drought stress effect on winter wheat development, growth (leaf area index), soil moisture and yields. Simultaneously, the ability of Hermes crop growth model to simulate drought stress response was tested. The field trial was established at Domanínek station (Bystřice nad Pernštejnem district, Czech Republic) in 2014. Mobile rain-out shelters for precipitation reduction were installed on the plots of winter wheat in May 2015. Results of this study showed that model is able to reproduce well a soil moisture content and to certain extent the drought stress for grain yields of winter wheat. Using the rain-out shelters (from 19 May to harvest on 6 August 2015), real winter wheat yields were reduced by 1.7 t/ha. The model was able to estimate the average yield with a deviation of 0.15 t/ha (6%) for no stressed variant. Model underestimated the yields for sheltered variant with a difference 0.67 t/ha (71%) on average against observed yields.
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Equipment for automatic watering of plants
Vavroš, Ondřej ; Fedra, Zbyněk (referee) ; Prokeš, Aleš (advisor)
This bachelor project deals with design of converter of soil moisture into usable data format using moisture sensors and microcontroller Silicon Laboratories C8051F120 series and evaluation kit to care for plants, especially their irrigation. Furthermore, the project deals with the development of software modules for converters operation and operation of irrigation.
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Pedotransfer functions for estimation of moisture retention curves of medium-heavy soils of South Moravia
Gavlasová, Iva ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
The most important characteristics of each soil is its hydro-physical properties, which include retention curve. Retention curve expresses the relationship between humidity and pressure head. It is course affected by many factors such as grain size and mineralogical composition, humus content, structure and bulk density of dry soil. This thesis deals with direct and indirect determination of one of the basic hydraulic characteristics of the soil, soil moisture retention curve. For laboratory determination of moisture retention curves were used for sand tank and pressure instruments. Measured body retention curves were optimized RETC program.For indirect determination of retention curves were used Pedotransfer function by Wösten et . al .(1998 ) , derived from the European soils and under HYPRES Šútora and Štekauerová (2000). As in the project Wösten et al . (1998), PTF were processed for arable land in the area. The accuracy of both models PTF was assessed by the correlation coefficient R and standard error RMSE. Simple models PTF provide estimates of retention curves with sufficient accuracy for practical use in the locality.
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Determination of soil hydraulic characteristics in the selected location
Stoklásková, Adéla ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
This thesis deals with direct and indirect determination of soil hydraulic characteristics (retention curve and hydraulic conductivity) in the locality of Bohaté Málkovice. For laboratory determination of soil moisture retention curve is used sand tank and pressure relief device. For the indirect determination of soil hydraulic characteristics is used computer software Rosetta, which includes 5 models of pedotransfer functions. For estimatiton of retention curves are applied previously derived pedotransfer function (continuous parametric PTF and point PTF).
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Wireless sensors network for measurement of soil water potential
Rášo, Peter ; Klusáček, Stanislav (referee) ; Havránek, Zdeněk (advisor)
Cílem tohoto projektu je vytvoření bezdrátové senzorické sítě na měření sacího potenciálu půdy. Práce obsahuje výběr vhodné měřící metody obsahu vody v půdě, jejíž součástí je i tvorba kalibrač˘ní křivky. Dále se zabývá realizací hardwaru a firmwaru pro dva typy modulů. Stanice end station, obsahující snímač˘e, a základní stanice base station, která přijímá a přeposílá data. Celá aplikace je doplněna o uživatelský program, který umožňuje zálohování dat, zobrazování průběhů dat včetně dat předchozích, změnu nastavení systému spolu s možností žádosti o potřebné informace.
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Drivers of soil moisture trends in the Czech Republic between 1961 and 2012
Trnka, Miroslav ; Brázdil, Rudolf ; Balek, J. ; Semerádová, Daniela ; Hlavinka, Petr ; Možný, M. ; Štěpánek, Petr ; Dobrovolný, Petr ; Zahradníček, Pavel ; Dubrovský, Martin ; Eitzinger, Josef ; Fuchs, B. ; Svoboda, M. ; Hayes, M. ; Žalud, Zdeněk
Soil moisture dynamics and their temporal trends in the Czech Republic are forced by various drivers. Our analysis of temporal trends indicates that shifts in drought severity between 1961 and 2012 and especially in the April, May, and June period, which displayed such results as a 50% increase in drought probability during 1961–1980 in comparison to 2001–2012. We found that increased global radiation and air temperature together with decreased relative humidity (all statistically significant at p < 0.05) led to increases in the reference evapotranspiration in all months of the growing season; this trend was particularly evident in April, May, and August, when more than 80% of the territory displayed an increased demand for soil water. These changes, in combination with the earlier end of snow cover and the earlier start of the growing season (up to 20 days in some regions), led to increased actual evapotranspiration at the start of the growing season that tended to deplete the soil moisture earlier, leaving the soil more exposed to the impacts of rainfall variability. These results support concerns related to the potentially increased severity of drought events in Central Europe. The reported trend patterns are of particular importance with respect to expected climate change, given the robustness and consistency of the trends shown and the fact that they can be aligned with the existing climate model projections. Introduction
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Vegetation succession in old fields at broad landscape scales
JÍROVÁ, Alena
This thesis is focused on succession in old fields in Central Europe. Repeated sampling, analysis of surrounding vegetation and soil measurements were conducted in the Bohemian Karst Landscape protected area. Samples from the Doupovské hory Mountains and the rest of the Czech Republic were added to discover basic principles of old field succession at the larger scale of landscapes.
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