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Use of nanomagnets treated materials in study of decomposition
Vyhnálek, Michal ; Frouz, Jan (advisor) ; Veselá, Hana (referee)
In study of soil organic matter, many methods of carbon labeling are used, mostly using carbon isotope 13 C, which are reliable, but require expensive devices. Magnetic nanoparticles could provide low-cost alternative, which can be prepared in most laboratories with basic equipment. The upside of nanoparticles usage is the fact, that we could monitor fate of individual particles added to soil, including their chemical transformations or changes in microbial communities. The goal of this paper was to test the usage of magnetic nanoparticles and prove the reliability of carbon labeling through experiment. KEY WORDS Magnetic nanoparticles, decomposition, soil organic matter
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Kvalifikace primární půdní organické hmoty podle rychlostní konstanty oxidace v půdách s odlišným systémem zpracování
SLÁDKOVÁ, Jana
Soil organic matter is considered to be one of the most frequently discussed topics among professional associations and scientists. Both the content and the quality of soil organic matter radically influences not only the physical and chemical properties of soils but also the ecosystem services that soils provide. Many methods have been originated regarding the evaluation of quality and quantity of soil organic matter during scientific research. It seems that most of the methods employed in agricultural practices are encumbered by certain shortcomings. Principles of newly discovered methods of evaluating soil organic matter are described in this thesis. These principles proceed from dividing the portion of organic material into stable and unstable organic matter. We evaluated the quality of organic material from different sampling techniques (e.g. ploughing, disc harrow, deep tillage). The results have shown that different ways of cultivation influence the amount of quantitative and qualitative parameters of soil organic matter. For example we discovered the impact of cultivation on the quantity of soil organic carbon or on the quality of primary soil organic matter
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Experimentální stanovení vybraných fyzikálních parametrů půd pro potřeby počítačového modelování utužení půd v důsledku pojezdu zemědělské techniky.
HALÍŘ, Vladimír
The aim of the thesis was to experimentally determine the selected physical parameters of soil samples with the output of data usable for the needs of computer modeling and simulation of soil compaction as a result of soil loading by agricultural machinery. Output data should be expediently consolidated according to the proposed primary data synthesis proposals, taking into account the obviousness and clarity of the operating influences useful under normal agricultural practice. The practical part deals with the diagnosis of relevant factors determining and affecting the technological and consistency properties of soil samples with a focus on the content factor of the added organic soil organic matter. The output of the thesis is both the raw data of the model sample series in the form of graphical dependencies of the selected specification factors within the range of the defined intervals, as well as the outline of the design of a range of cooperative interconnections with the possibility of data evaluation, with the support of a sophisticated program for the creation of computer multiphysical simulations such as COMSOL MULTIPHYSICS?.
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Assessment health/quality of the soil near the village Bohaté Málkovice
Suchá, Kateřina ; Doležal, Petr (referee) ; Kameníčková, Ivana (advisor)
Diploma thesis evaluates quality and healthiness of the soil health located close to Bohate Malkovice focusing on changes in both physical and chemical characteristics of the soil in time. The theoretical part describes physical, chemical, and biological parameters of the soil. Selected physical parameters are structure, texture, determination of measured weight, bulk density of the soil, porosity, actual volumetric water content of the soil, aeration, saturated and unsaturated hydraulic conductivity, infiltration, and colour. Chosen chemical parameters are pH, carbonates, soil electrical conductivity, and humus content. Picked biological parameters are microbial biomass, respiration, nitrogen content, and weed infestation. The practical part analyses selected indicators of quality of the soil from the location of the experiment close to Bohate Malkovice. The area under evaluation has been treated using reduced tillage for long term. The practical part is based on the laboratory examination of disturbed and undisturbed soil samples taken between years 2016 and 2018. Based on outcome results we can evaluate the quality of the soil considering plants growth, development, and soil fertility.
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Environmental aspects of the cultivation of selected energy crops
KOPECKÝ, Marek
This dissertation aims primarily at determining the energy yield that can be produced, if certain species of energy crops are grown (under various regimes of fertilizing and sowing) by the Faculty of Agriculture, the University of South Bohemia, on a university's trial parcel. Zea mays L. is one of the energy crops chosen for the experiment; it is grown on a large area in the Czech Republic nowadays. Perennial crops of Phalaris arundinacea L., Elymus elongatus subsp. ponticus cv. Szarvasi-1 andMiscanthus × giganteus were also chosen for this experiment. Based on the collected data, a risk of erosion provoked by the above-mentioned crops has been determined by using USLE method. The crop stands and the soil have been analysed too. This analysis has focused on the organic matter evaluation, by using a brand new method. Last but not least, occurrence of Carabidae beetles has been studied and evaluated within the research; they are considered bio indicators of the environmental conditions. Our experiment has shown that Zea mays L. is the most high-yielding species. On the other hand, Phalaris arundinacea L. has not produced positive results; the most high-yielding variation of it only made a half yield of Zea mays L. In contrast to Zea mays L., grass species of Phalaris arundinacea L. andElymus elongatus have had an extraordinary anti-erosion capacity. Studying the amount of primary organic matter in the soil, we have found almost double amount of it in Miscanthus × giganteus andZea mays L. crop stands, compared to another two species. Monitoring oxidation reaction kinetics of the primary organic matter, we could count the oxidation speed constant of k. There have been dramatic differences between the individual soil samples. However, the data file is too complicated to draw the general conclusion from. On the other hand, evaluating the data gathered by studying Carabidae beetles and the environmental values of the crops stands, we have found out the crop stands are not too valuable from the environmental point of view. We have found out the perennial species have got an extraordinary anti-erosion capacity. We recommend Miscanthus × giganteus and Elymus elongatus, in particular, as an alternative to corn, especially to regions highly endangered by erosion.
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Relationship between thermo-oxidative stability and soil quality indicators
Svatoň, Karel ; Doležalová Weissmannová, Helena (referee) ; Kučerík, Jiří (advisor)
This diploma thesis focuses on the use of thermogravimetry as quick and low-cost method in the analysis of soil quality. Most of the currently used methods for analyzing some soil properties are, unlike thermogravimetry, demanding especially for pretreatment and analysis time. Previous research has shown an interesting correlation between thermogravimetry data and some soil properties, but to obtain these correlations, it is necessary to keep the analyzed soils at 76% relative humidity. The aim of this work was to determine whether similar correlations can also by achieved at lower relative humidities. Therefore, soil samples in this work were thermogravimetrically analyzed at 43% relative humidity. That humidity is closer to laboratory conditions and it is also easier to be reached by most of commercially available thermogravimeters. Next aim of this thesis was to find whether thermogravimetric data correlate with other soil properties, especially microbiological indicators of soil quality. Results showed that thermogravimetry of soil samples correlates with standard methods even at 43% humidity. Furthermore, it was found that they also correlate with selected microbiological parameters, such as anaerobic ammonification or urease activity. These results suggest the possibility of using thermogravimetry analysis at broader spectrum of soil properties, without the need for pretreatment of samples and at different (relevant) soil moisture.
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Stability of soil organic matter and humic substances
Nováková, Šárka ; Enev, Vojtěch (referee) ; Klučáková, Martina (advisor)
This diploma thesis is focused on changes of stability in organic matter by extraction in different agents. Two soils of a different type and isolated humic acids were used for stability determination. Extraction agents were selected usually used for soil metal extraction, and a changes in the structure of the organic matter was observed. Samples were characterized using FTIR analysis and elemental analysis, the extracts were measured by UV-VIS spectroscopy, absorption ratios E2/E3, E4/E6 were discovered, dynamic light scattering were determined for particle size distributions. Next part of the thesis was the assessment of the change of thermal stability using thermogravimetric analysis and differential scanning calorimetry, degradation temperatures of the extracted samples were discovered and compared with the original samples.
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Water-cation bridges in soil organic matter
Starostová, Anna ; Komendová, Renata (referee) ; Kučerík, Jiří (advisor)
Degradace půdy zasolováním, zvyšující se teplota a následný úbytek mnonžství srážek v posledních letech vedou k rozšiřování aridních a semi-aridních oblastí (v současnosti pokrývají třetinu pevniny Země). Navíc představují globální environmentální problémy, které, pokud se nebudou správně řešit, můžou vést k vážné celosvětové krizi. V této diplomové práci jsme propojili tato témata a zaměřili se na lepší porozumění role sodných kationtů na vazbu vody v půdní organické hmotě v aridních a semi-aridních podmínkách. Náš cíl byl prozkoumat proces vzniku a stabilitu vodních molekulových můstků a vodních-kationických můstků v půdní organické hmotě, sílu vazby a množství vázáné vody v půdě za využití diferenční kompenzační kalorimetrie. Nasycení sodnými kationty bylo studováno ve dvou koncentračních oblastech. Na simulaci přirozených podmínek v půdách bylo použito nasycení vazebných míst sodnými kationty do 100% a nasycení nad 100% reprezentovalo vysoce zasolené půdy. Výsledky potvrdily význam schopnosti půdy získávat vodu ze vzdušné vlhkosti, podíl vody v půdě vzrůstal s relativní vlhkostí. Vyšší podíl vody v půdě pak způsoboval snížení síly vazebných interakcí, což bylo interpretováno jako fakt, že rovnováha mezi půdní a vzdušnou vlhkostí vede k optimální vlhkost půdy. Přítomnost sodných kationtů ve vzorcích do nasycení 100% měla na množství vody zanedbatelný vliv, ale v přesycených vzorcích umožňovala navázání většího množství vody. V přesycených vzorcích bylo také pozorováno zvýšení síly vazebných interakcí mezi půdou a vodou, což vede k její větší zádrži. Molekulové můstky byli stabilnější ve vzorcích, které obsahovaly Na+. Nejvyšší stabilita byla pozorována u 10% nasycených vzorcích, další zvyšování Na-saturace pak již vedlo k snižování stability molekulových můstků. Hlavním výstupem práce je, že tvorba vodních-kationických můstků stabilizuje půdní strukturu a že má vlyv na sílu a množství vody vázané v půdě, což představuje klíčové aspekty kvality půdy. Je potřebný rozsáhlejší výskum tohoto tématu, aby získané výsledky pomohli optimalizovat půdní manažment v aridních oblastech a také v ostatních oblastech, kde dochází k degradaci půdy.
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Kvalifikace primární půdní organické hmoty podle rychlostní konstanty oxidace v půdách porostů energetických rostlin
SKOBA, David
This Bachelor thesis is focused on monitoring the yield parameters of selected energy plants (Elymus elonganus, Phalaris arundinacea L., Miscanthus × giganteus). First part of the work was performed at the experimental site of the Faculty of Agriculture of the University of South Bohemia in České Budějovice, where long-term experiments were carried out to look at the yields of these plants. I was observing the yield of crops grown for the purpose of incineration, which are harvested once a year before the beginning of the growing season. Research has shown that on a 4-year average the most profitable species is Miscanthus × giganteus. The second practical part of my work was the sampling and analysis of soil samples from these stands and, for comparison, the sampling of soil under permanent grassland. In the laboratory at the Department of Agroecosystems the samples were modified and examined in terms of the quantity and quality of soil organic matter. The analysis shows that the content of humus in soils with energy plants is lower in comparison to the content of these substances in soil under permanent grassland. There were no significant differences in the observed values of the velocity constants of the oxidation of the primary soil organic matter.
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