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Development of New Application Forms of Humic Substances for Agricultural and Environmental application
Kratochvílová, Romana ; Kráčalík, Milan (referee) ; Salaš, Petr (referee) ; Klučáková, Martina (advisor)
The new forms of superabsorbent polymers (SAP) on the base of acrylic acid were developed and studied in this thesis. The SAP are focused on agricultural and environmental applications. While they are applied to the soil, SAP can prevent water losing and they become a reservoir of humidity in case of dry season, moreover in combination with fertiliser they play role of controlled release medium. Eight various samples of SAP were experimentally prepared by networking of partially neutralized acrylic acid. Potassium peroxydisulfate was used as the initiator and N,N–methylenebisacrylamide as the crossing agent. Some of samples contained addition of second monomer of acrylamide. All of them were enriched by fertilisers – natural lignohumate or synthetic NPK or combination of both. The swelling characteristics of prepared samples were investigated in conditions of various ionic strength. The influence of xerogels’ particles size on swelling properties was also observed. The viscoelastic characteristics of hydrogel form of all SAP were determined by using of rotation rheometer. The changing of viscoelastic properties were studied in dependence on time, on freezing and on repeating swelling cycles. On top of that the controlled releasing ability of SAP was tested due to three modelling experiments. The biological activity of all polymer products was tested at the end of the thesis. All samples of SAP were incorporated into the artificial soil and the ability of the water retention in the soil was observed. The growing experiments were running by using of corn plants. The size and the mass of each plant were measured and branching of the root was objectively evaluated by programme Harmonic and Fractal Image Analyzer.
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Transport of humic substances through plant cuticle
Smilková, Marcela ; Salaš, Petr (referee) ; Weidlich, Tomáš (referee) ; Klučáková, Martina (advisor)
Doctoral Thesis is aimed on the transport of liquid preparations chemically based on potassium lignohumate through plant cuticles commonly utilized in agricultural applications. Firstly, the thesis deals with optimization and correct mathematical description of diffusion experiments. Transport (diffusion) experiments have been realized in model hydrogel media based on linear polysaccharide – chemically inert agarose. Diffusion experiments have been realized by two independent approaches (diffusion models) – free diffusion of lignohumate in hydrogel and diffusion pair (hydrogel-hydrogel), where one of these was enriched by lignohumate in contrast with the second one. Plant cuticle, as the major barrier on the leaves, isolated from Prunus laurocerasus, was used as porous membrane in diffusion experiments. The main aim of Ph.D. thesis was the characterization of barrier properties of cuticles, which are the most limiting barrier regulating the transport of lignohumate in/out the leaves during foliar fertilization. These experimental problems have been solved by diffusion experiments and by their proper mathematical description, especially by the determination of fundamental diffusion parameters such as effective diffusion coefficients. These parameters have been used for the modelling of concentration profiles in hydrogels and comparison with experimental data. Significant part of thesis is aimed on the determination of physico-chemical properties of plant cuticles and hydrogels matrixes utilized as model diffusion environment. These characteristics are subsequently correlated with transport (diffusion) parameters. Plant cuticles have been isolated from Prunus laurocerasus leaves and then were characterized by relevant instrumentation notably with respect to their structure and penetration through of lignohumate. Hydrogels have been characterized with respect to mechanical (viscoelastic) (rheology), morphological e.g. porosimetry) and structural (scanning electron microscopy) properties. Mentioned properties have direct link to transport processes ongoing in these materials. Next part of doctoral thesis is aimed on the proper and correct interpretation of experimental results obtained from glass-house experiments. During these experiments, hydrogels based on superabsorbent polymers developed on Faculty of Chemistry, Brno University of Technology, have been used together with commercial preparation – potassium lignohumate kindly provided by co-working commercial subject – Amagro s.r.o. The main aim was the application of lignohumate directly on plants through root system. Results of these experiments should confirm the positive effect on plant growth as well as their positive development. Results obtained from transport/diffusion experiments confirm that the penetration of active compounds (lignohumate) is more efficient in comparison with adaxial cuticles. The kinetics of lignohumate transport is faster for abaxial cuticles. From superabsorbent experiments it is obvious that these play significant role in growth and development of plant and simultaneously positively contribute to creation of suitable conditions for proper microbiological and bacterial activity, which is essential for health soil.
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Lignite degradation in soil environment
Vybíralová, Natálie ; Salaš, Petr (referee) ; Pekař, Miloslav (advisor)
This Master‘s thesis deals with the topic of coal and, more precisely South Moravian lignite. Lignite was degraded by using biological and chemical methods, which included oxidation of lignite with hydrogen peroxide. Special attention was paid to the degradation of lignite in the soil environment, where the simulation of natural fields conditions took place for 6 months. Furthermore, a simulation of root exudates was carried out using organic acids, which occur naturally in the soil environment and directly affect life in the soil and around the roots of the plant. Lignite degradation was also performed using a cultured bacterial solution and then using a commercially available horticultural products to increase the activity of soil microorganisms and promote growth.
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Transport of humic substances through plant cuticle
Smilková, Marcela ; Salaš, Petr (referee) ; Weidlich, Tomáš (referee) ; Klučáková, Martina (advisor)
Doctoral Thesis is aimed on the transport of liquid preparations chemically based on potassium lignohumate through plant cuticles commonly utilized in agricultural applications. Firstly, the thesis deals with optimization and correct mathematical description of diffusion experiments. Transport (diffusion) experiments have been realized in model hydrogel media based on linear polysaccharide – chemically inert agarose. Diffusion experiments have been realized by two independent approaches (diffusion models) – free diffusion of lignohumate in hydrogel and diffusion pair (hydrogel-hydrogel), where one of these was enriched by lignohumate in contrast with the second one. Plant cuticle, as the major barrier on the leaves, isolated from Prunus laurocerasus, was used as porous membrane in diffusion experiments. The main aim of Ph.D. thesis was the characterization of barrier properties of cuticles, which are the most limiting barrier regulating the transport of lignohumate in/out the leaves during foliar fertilization. These experimental problems have been solved by diffusion experiments and by their proper mathematical description, especially by the determination of fundamental diffusion parameters such as effective diffusion coefficients. These parameters have been used for the modelling of concentration profiles in hydrogels and comparison with experimental data. Significant part of thesis is aimed on the determination of physico-chemical properties of plant cuticles and hydrogels matrixes utilized as model diffusion environment. These characteristics are subsequently correlated with transport (diffusion) parameters. Plant cuticles have been isolated from Prunus laurocerasus leaves and then were characterized by relevant instrumentation notably with respect to their structure and penetration through of lignohumate. Hydrogels have been characterized with respect to mechanical (viscoelastic) (rheology), morphological e.g. porosimetry) and structural (scanning electron microscopy) properties. Mentioned properties have direct link to transport processes ongoing in these materials. Next part of doctoral thesis is aimed on the proper and correct interpretation of experimental results obtained from glass-house experiments. During these experiments, hydrogels based on superabsorbent polymers developed on Faculty of Chemistry, Brno University of Technology, have been used together with commercial preparation – potassium lignohumate kindly provided by co-working commercial subject – Amagro s.r.o. The main aim was the application of lignohumate directly on plants through root system. Results of these experiments should confirm the positive effect on plant growth as well as their positive development. Results obtained from transport/diffusion experiments confirm that the penetration of active compounds (lignohumate) is more efficient in comparison with adaxial cuticles. The kinetics of lignohumate transport is faster for abaxial cuticles. From superabsorbent experiments it is obvious that these play significant role in growth and development of plant and simultaneously positively contribute to creation of suitable conditions for proper microbiological and bacterial activity, which is essential for health soil.
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Development of New Application Forms of Humic Substances for Agricultural and Environmental application
Kratochvílová, Romana ; Kráčalík, Milan (referee) ; Salaš, Petr (referee) ; Klučáková, Martina (advisor)
The new forms of superabsorbent polymers (SAP) on the base of acrylic acid were developed and studied in this thesis. The SAP are focused on agricultural and environmental applications. While they are applied to the soil, SAP can prevent water losing and they become a reservoir of humidity in case of dry season, moreover in combination with fertiliser they play role of controlled release medium. Eight various samples of SAP were experimentally prepared by networking of partially neutralized acrylic acid. Potassium peroxydisulfate was used as the initiator and N,N–methylenebisacrylamide as the crossing agent. Some of samples contained addition of second monomer of acrylamide. All of them were enriched by fertilisers – natural lignohumate or synthetic NPK or combination of both. The swelling characteristics of prepared samples were investigated in conditions of various ionic strength. The influence of xerogels’ particles size on swelling properties was also observed. The viscoelastic characteristics of hydrogel form of all SAP were determined by using of rotation rheometer. The changing of viscoelastic properties were studied in dependence on time, on freezing and on repeating swelling cycles. On top of that the controlled releasing ability of SAP was tested due to three modelling experiments. The biological activity of all polymer products was tested at the end of the thesis. All samples of SAP were incorporated into the artificial soil and the ability of the water retention in the soil was observed. The growing experiments were running by using of corn plants. The size and the mass of each plant were measured and branching of the root was objectively evaluated by programme Harmonic and Fractal Image Analyzer.
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Production of strawberries in organic system of growing
Pištěková, I. ; Boček, S. ; Vaňková, Radomíra ; Drahošová, H. ; Odstrčilová, L. ; Salaš, P. ; Sasková, H.
A technology of growing strawberries in organic farming systems is presented in the methodology. The methodology is aimed at selecting the most suitable varieties of strawberry, previous crop influence, the influence of supplementary plant products and biofungicides on the yield of single varieties. It contains evaluation of health condition and fruiting characteristics of varieties. Yield potential of varieties and resistance to diseases were found in the most suitable varieties and technological processes for organic cultivation of strawberries were selected. The methodology for practice is a comprehensive guide for growing strawberries in organic production systems.
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