|
|
Study on the Effect of Biochar Application on Organic Matter in Soil
Kurková, Marie ; Sovová, Šárka (referee) ; Kalina, Michal (advisor)
This bachelor thesis studies the effect of the application of biochar on the composition of organic matter of two different soil samples. Specifically, the total content of organic matter in the soil and the ratio of humic and fulvic acids in these soils before and after the application of biochar were monitored. The composition of the soil mass was also observed thermogravimetrically and by using the certified method of humic and fulvic acids isolation from samples of studied soils. Furthermore, the effect of biochar on the growth of a model plant (maize – Zea mays) was observed. From this point of view, differences in plant growth were possible to observe from the beginning of the experiment, both in comparison with samples with and without biochar and in comparison with samples containing different doses of biochar. The type of soil used for cultivation experiments also influenced on plant growth.
|
|
|
The Influence of Microbial Degradation of Biochar in Soil on its Physico-chemical Properties
Kurková, Marie ; Weidlich, Tomáš (referee) ; Kalina, Michal (advisor)
This master‘s thesis studies the different factors that can affect biochar in soil and cause its degradation. These factors include irrigation, root exudates and the action of microorganisms. In the experimental part, the degradation of biochar in the soil environment was studied in two ways, firstly without the action of microorganisms, where the effect of irrigation was simulated by leaching biochar in ultrapure distilled water and model rainwater, and the effect of root exudates was simulated by extracting of biochar in citric acid as a model root exudate of maize sown. The extracted biochar solutions without prior cultivation in soil were characterized by pH, conductivity, UV-VIS analysis and elemental analysis. The biochar residues after extractions were characterized for morphology by SEM, structural differences by FTIR, and organic and mineral content by TGA analysis. The biochar samples after cultivation in soil were subjected to extractions under the same conditions and the same analyses were performed. The effect of cultivation in soil on biochar resulted in a change in elemental composition, a decrease in biochar alkalinity and changes in the ratio of organic matter and mineral fraction were observed. The decrease in pH and conductivity of biochar was mainly related to potassium leaching. The structural and morphological analysis indicated that there is no significant degradation of the structure of the biochar due to washing or cultivation in soil, but there is a partial fouling of the biochar pores by low molecular weight impurities from the soil. These results suggest a short-term action of biochar in soils as a source of nutrients (potassium, phosphorus) and, conversely, a long-term action as a soil conditioner.
|
|
|
The Influence of Microbial Degradation of Biochar in Soil on its Physico-chemical Properties
Kurková, Marie ; Weidlich, Tomáš (referee) ; Kalina, Michal (advisor)
This master‘s thesis studies the different factors that can affect biochar in soil and cause its degradation. These factors include irrigation, root exudates and the action of microorganisms. In the experimental part, the degradation of biochar in the soil environment was studied in two ways, firstly without the action of microorganisms, where the effect of irrigation was simulated by leaching biochar in ultrapure distilled water and model rainwater, and the effect of root exudates was simulated by extracting of biochar in citric acid as a model root exudate of maize sown. The extracted biochar solutions without prior cultivation in soil were characterized by pH, conductivity, UV-VIS analysis and elemental analysis. The biochar residues after extractions were characterized for morphology by SEM, structural differences by FTIR, and organic and mineral content by TGA analysis. The biochar samples after cultivation in soil were subjected to extractions under the same conditions and the same analyses were performed. The effect of cultivation in soil on biochar resulted in a change in elemental composition, a decrease in biochar alkalinity and changes in the ratio of organic matter and mineral fraction were observed. The decrease in pH and conductivity of biochar was mainly related to potassium leaching. The structural and morphological analysis indicated that there is no significant degradation of the structure of the biochar due to washing or cultivation in soil, but there is a partial fouling of the biochar pores by low molecular weight impurities from the soil. These results suggest a short-term action of biochar in soils as a source of nutrients (potassium, phosphorus) and, conversely, a long-term action as a soil conditioner.
|
|
|
Study on the Effect of Biochar Application on Organic Matter in Soil
Kurková, Marie ; Sovová, Šárka (referee) ; Kalina, Michal (advisor)
This bachelor thesis studies the effect of the application of biochar on the composition of organic matter of two different soil samples. Specifically, the total content of organic matter in the soil and the ratio of humic and fulvic acids in these soils before and after the application of biochar were monitored. The composition of the soil mass was also observed thermogravimetrically and by using the certified method of humic and fulvic acids isolation from samples of studied soils. Furthermore, the effect of biochar on the growth of a model plant (maize – Zea mays) was observed. From this point of view, differences in plant growth were possible to observe from the beginning of the experiment, both in comparison with samples with and without biochar and in comparison with samples containing different doses of biochar. The type of soil used for cultivation experiments also influenced on plant growth.
|
|
|
Application of mathematical models for simulation of hydrological conditions in selected streams
Kurková, Marie ; Vašků, Zdeněk (advisor) ; Michal, Michal (referee)
Flood is a natural phenomenon that occurs at different intensities and irregular time intervals. As to natural disasters, floods represent the greatest direct threat for the Czech Republic. They may cause serious critical situations during which not only extensive material damages are done, but may bring also losses of the lives of inhabitants in affected areas as well as vast devastation of cultural landscape including environmental damages. Important from the viewpoint of the elimination of potential threats and consequences of such events is the information issued by flood forecasting service about the character and size of flood areas for individual N-year flood discharges and specific flood scenarios. An adequate image of depths and flow rates in the longitudinal or cross profile of the watercourse during a flood event is provided by the hydrodynamic model. This is why the information obtained from the hydrodynamic models occupies a privileged position from the viewpoint of the protection of citizens' lives and mitigation of damage to their property. The first study is situated on the river Úhlava in meadows by Příchovice near the town Přeštice. The proposal of flood-protection measures is contained in Territorial control documentation. The documentation was elaborated on the basis of hydraulic calculations and experiences from the flood in August 2002. The mathematical model is practically used in the study of analysis of proposed flood-protection measures. The analysis is based on mathematical simulation of water outflow and water level on the river Úhlava. It is possible to use the non-commercial software Hec-Ras, version 3.1.1., for the simulation itself. One of the points of view of the possibility of using proposed flood-protection measures is total efficiency. The mathematical model is posssible to use as a basis of support for realization of proposed flood-protection measures on the river Úhlava in meadows by Příchovice within the grant programme "Program prevence před povodněmi II" under the control of the Ministry of Agriculture. In the second case the mathematical model is practically used in the study of hydrotechnical analysis of streams in cadastral unit. The analysis is based on matjematical simulation of water outflow and water level on chosen streams. It is possible to use the noncomercial software HEC-RAS for the own simulation. The analysis should be shown on dangerous places in the interest place. The mathematical model is possible of using to use as basis for revaluation of action in spatial plan or for view of the flood-protection measures in the village Mochtín. Basic input into the hydrodynamic models is represented by altimetry data. One of ways to obtain such data is through the method of aerial laser scanning (ALS) from the digital relief model (DRM). This method is considered one of the most accurate methods for obtaining altimetry data. Its bottleneck is however incapacity of recording terrain geometry under water surface due to the fact that laser beam is absorbed by water mass. The absence of geometric data on watercourse discharge area may perceptibly affect results of modelling, especially if a missing part of the channel represents a significant discharge area with its capacity. One of methods for eliminating the deficiency is a sufficient channel recess by means of software tools such as CroSolver. The third submitted paper deals with the construction of a hydrodynamic model using 5th generation DRM data, and compares outputs from this model at various discharges with a model based on the altimetry data modified by using the CroSolver tool. Outputs from the two hydrodynamic models are compared in HEC-RAS programme with the use of recessed data and with the use of unmodified DRM. The comparison is done on the sections of two watercourses with different terrain morphology and watercourse size. A complementary output is the comparison of inundation areas issuing from both model variants. Our results indicate that differences in the outputs are significant namely in the lower discharges (Q1, Q5) whereas for Q50 and Q100 the difference is negligible with a great role being played by morphology of the modelled area and by the watercourse size.
|
guest ::
RSS feed.