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The influence of roots on the chemical properties of the apoplast and the rhizosphere
Puldová, Kristýna ; Fendrych, Matyáš (advisor) ; Šámalová, Markéta (referee)
Chemical properties of the apoplast and rhizosphere are crucial for plant development and its overall well-being. Apoplast includes space outside the plasma membrane and its content, such as gas, water, and solutes. Changes in apoplast properties significantly influence various processes. One of them is cellular growth - the pH-dependent extension of cell walls. The rhizosphere is the soil environment near and under the influence of roots. It is characterised by abiotic factors like the availability of nutrients and toxic compounds. It is also a space with a high representation of microbiome communities. Plants can significantly influence the chemical properties of both apoplast and rhizosphere to improve their growth conditions. This thesis summarises the most important mechanisms of plants' roots that change these chemical properties, focusing on the model plant Arabidopsis thaliana. It shows how and where these mechanisms intersect and in which way they influence each other. Emphasis is placed on the process of growth regulation and mechanisms of increasing nutrient availability. Keywords: apoplast, rhizosphere, H+ ATPase, root growth, rhizodeposition, root exudates, nutrients, microbiome
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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.
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Enzymatic Degradation of Biochar
Zmijová, Marie ; Enev, Vojtěch (referee) ; Kalina, Michal (advisor)
Human prosperity is inextricably linked to healthy soil. It turns out that the application of biochar improves soil properties and, as a result, also the growth and yield of plants. The presence and activity of soil biota contributes to soil quality, but it also excretes compounds that can degrade biochar. Experiments simulating the action of enzymes and root exudates were carried out in order to find out whether there are physico-chemical changes in biochar. Three biochars, which were chosen for this purpose were degraded using an H2O2 solution, simulating enzymatic action. Samples were subsequently analyzed using TGA, FTIR, SEM and contact angle measurement. It was found that the amount and type of degraded biochar matter depends on the parameters of its production. The amount of functional groups containing oxygen on the surface of biochar rises due to enzymatic oxidation and the surface’s hydrophobicity decreases as a result. An extraction test using citric acid, a root exudate representative, showed that the sample had been washed more effectively, leading to a higher proportion of organic matter in the biochars. In the obtained leachates, the amount of elements released from the biochar was monitored using ICP-OES. The initial washing led to the release of the largest amount of micro and macro elements, which caused a decrease in the pH value of the solution and an increase in conductivity. The pH value of the solution had a major influence on the amount of released multivalent elements (Ca, Mg). The combination of these changes that may occur in the soil system probably does not change the desired effect of biochar and its use may be beneficial in the long term.
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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.
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Vliv aplikace kompostu na fyzikalní, chemické a mikrobiologické vlastnosti degradované půdy
Svoboda, Zdeněk
The influence of the application of compost on the physical, chemical and microbiological qualities of degraded soil This diploma thesis is aimed at the influence of compost on the physical, chemical and microbiological qualities of degraded soils. The principal aim of the thesis is to answer the question whether the amelioration of the soil fertility after the application of compost could be attributed only to the changes of physical and chemical qualities of soil, or to the increase of soil microbial activity, or to the combination of both these possibilities. For answering the question, soil degraded by long-term application of mineral fertilizers was chosen and laboratory experiment was designed. The soil comes from the locality Březová nad Svitavou. The following parameters were monitored in the experiment: dry basis of the plant, leakage of ammonium and nitrate ions, physical parameters of soil, mycorrhiza, root exudate and their influence on microbial respiration. The obtained results prove that the application of compost improves soil fertility, especially thanks to the changes of physical and chemical parameters of soil.
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