|
|
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.
|
|
|
Obsah organického uhlíku v orniční a podorniční vrstvě půdy v porostech energetických trav
BLÁHA, David
The study aimed to determine the total content of organic carbon in the topsoil and subsoil layer of energy grasses (Dactylis glomerata, Elymus elongatus subsp. ponticus cv. Szarvasi-1, Festuca arundinacea, Phleum pratense). The plant cultures were established on 16 April 2019 at the experimental field of the Faculty of Agriculture and Technology, University of South Bohemia in České Budějovice. The organic carbon content was evaluated depending on the sampling depth and the fertilization variant. Soil sampling was taken at regular intervals with a pedological sounding rod from three depths (0-10 cm, 10-20 cm and 20-30 cm). The samples were adjusted for subsequent analysis on a Primacs SLC Analyzer in the Department of Agroecosystems laboratory. The highest content of total organic carbon was observed at 0-10 cm depth and the lowest at depth of 20-30 cm. Furthermore, a positive effect of fertilization on the total organic carbon content was found.
|
|
|
Organic carbon content in soils of energy crops
BLÁHA, David
The aim of the study was to determine the total content of organic carbon in the soils planted by selected energy plants (Dactylis glomerata, Elymus elongatus subsp. Ponticus, Festuca arundinacea, Phleum pratense). The plant cultures were established on 16. 4. 2019 at the experimental field of the Faculty of agriculture, University of South Bohemia, České Budějovice. The organic carbon content was monitored regularly depending on the depth of sampling and fertilization of variants. The first sampling was carried out before the plant culture establishment. Further samples were taken every 2 months. All of the samples were taken from the depth of 0-10 cm and 10-20 cm by pedological sounding rod. Subsequently, the samples were adjusted for the analysis and examined with the SKALÁR instrument in the laboratory at the Department of Agroecosystems. During the measurement, a sharp increase of organic carbon in the sample taken in the spring of 2020 was observed. A higher content of organic carbon was observed in the samples taken from the depth of 0-10 cm, though, statistically not significant. It was further found, that fertilization influences the total content of organic carbon. The fertilized variants showed higher values than unfertilized. The highest amount of total organic carbon was recorded at the Phleum pretense variant. However, the differences between the plants were not statistically significant.
|
|
|
Dynamika rybničního ekosystému z hlediska produckční ekologie
RUTEGWA, Marcellin
With the rise of environmental concerns, fish farmers are facing the challenge of maximizing fish production while maintaining the ecosystem integrity of fishponds. In semi-intensive ponds, fish production is based on the utilisation of the natural production potential of the pond ecosystem and supplementary feed. Understanding the sources and the fate of inputs in fishponds is crucial to assess the utilisation efficiency of these inputs and hence reduce nutrients and organic matter losses. Ecological integrity of ponds is not regularly assessed in the Czech Republic, where pond aquaculture is an important economic activity. Therefore, the quality of inflow, pond water and effluent were monitored in the Dehtář pond from 2014 to 2018. Nutrient and organic carbon budgets were used to quantify the sources and fates of nutrients and organic matter inputs in Dehtář. Assessment of ecosystem metabolic rates, plankton community composition, utilisation efficiency of nutrient and organic carbon inputs and nutrient retention were used to indicate the effect of fishery practices on the structure and functioning of the pond ecosystem. The transboundary layer model was used to determine and compare the levels of dissolved and diffusive methane (CH4) from two types of fishponds (main and nursery) differing in individual fish size of cultured common carp. The results showed that the Dehtář pond became hypereutrophic due to fishery management, namely high fish stock, associated weed fish, manuring and supplementary feeding. The phytoplankton assemblage was dominated by eutrophication tolerant species, including toxic cyanobacteria. Larger sized zooplankton disappeared from the pond due to the high grazing pressure of fish stock already in the spring. The major sources of phosphorus, nitrogen and organic carbon inputs to the pond were feed, water inflow and primary production, respectively. Accumulation in water and sediments were the main fate of nitrogen and phosphorus whereas respiration was the main fate of organic carbon. The utilisation efficiency of nutrient inputs was comparable to results from other studies but the utilisation efficiency of organic carbon inputs was rather lower. In general, this efficiency was low due to the poor quality and low digestibility of cereals used as fish feed and the inability to transfer the primary production to fish. The potential of the Dehtář pond to retain nutrients is comparable with other temperate lakes and reservoirs. This may be explained by a high load of nutrients, their assimilation by fish and phytoplankton, sedimentation and denitrification. However, during the fish harvest, part of the retained nutrients is released and discharged. Furthermore, it was found that unused organic matter partly fuels the production of methane, which is then released into the atmosphere. The methane concentration was higher in nursery ponds than in main ponds, but the diffusive methane emission did not differ much between the two types of ponds. Based on our present findings we highly recommend to conduct more research activities heading to more sustainable pond management practices that can maximize fish production while minimizing pollution risks in the fishponds and their catchments.
|
|
|
Dynamics of organic carbon in the ponds ecosystems
TOMKOVÁ, Iva
Ponds ecosystems are the most common type of lentic waterbodies in Czech Republic. In the last century, the quality of ponds water has been greatly influenced by intensive management in the catchment and ponds alone. As a result of the increasing concentration of nutrients, ponds lead to eutrophication. This is expressed as extensive primary production of phytoplankton and algal blooms. Decomposition of the accumulated organic matter affects the oxygen regime, pH and distribution of nutrients in the pond. Organic matter plays a key role in physical, chemical and biological processes in the ecosystem. The aim of the work was to describe the dynamics of organic carbon in the eutrophic ponds ecosystem with emphasis on its dissolved part (DOC). This study included evaluation of DOC concentration from 6 pond systems in the Třeboň region from 2010 to 2011 and a comparison with DOC concentrations from 2020. The relationship of DOC concentration to other chemical parameters of water was evaluated. It found that DOC concentration had no significant correlation with other parameters. The concentration of nutrients TN and TP had decreased over the last 10 years, while DOC concentration had increased. More detailed data from 5 ponds from 2008 to 2011 were evaluated in the same way. Optical methods such as absorbance and fluorescence were used to describe DOC dynamics. These methods were used to monitor 10 ponds from Třeboň and České Budějovice regions in 2017?2018. Data were compared between these regions because they differed in conductivity, but it had no differences in DOC concentration and other chemical parameters. The average value of DOC concentration was 14,8 mg l-1. The absorption characteristics of DOM such as spectral slope S275-295 and slope ratio SR suggested an autochthonous source of DOM. Specific absorbance values at 254 nm SUVA254 ranged from 1,4?3,0 l mgC-1 m-1 and indicates autochthonous substances with lower molecular weight and lower content of aromatics. SUVA254 values were higher in the Třeboň region, which indicates that there was a more allochthonous DOM with higher molecular weight and more aromatics in DOM in contrast to the České Budějovice region. Evaluation of seasonal changes in the composition of DOM using optical methods revealed that in the summer there were more autochthonous substances with lower molecular weight and lower aromatics DOM. SR values were negatively correlated to molecular weight and were higher in summer. FI and BIX values indicating autochthonous and microbial source DOM increased in summer. Optical methods were used for the first time to monitor the dynamics of organic matter in ponds.
|
|
|
Změny obsahu organického uhlíku a dusíku v půdě při obnovách travních porostů
Kadłubiec, Szymon
In the last 30 years there has been a big change in the acreage of permanent grasslands. Since 1990, the acreage of permanent grasslands has increased by 20% to 1003 thousand ha. Currently, there has been a decrease in the amount of cattle and sheep. Despite this fact, it is necessary to ensure high quality fodder from grasslands in order to assure profitability of farming. Therefore, farmers often opt for restoration. The most efficient way is radical ploughing restoration. This method involves numerous risks for environment. The present thesis examined the influence of radical restoration of grasslands by ploughing on the change in the content of organic carbon, total nitrogen and the C:N ratio in the soil. Field experiments were conducted in two locations on the land of National Stud at Kladruby nad Labem, and also in two locations in Oldřichovice near Třinec. In Kladruby, the samples were obtained from both, restored and indigenous grasslands, whereas in Oldřichovice, the samples were obtained only from restored grasslands. The biggest loss of organic carbon (Cox) and total nitrogen (Nt) was noted in Kladruby n.L. in the sandy soil of the original vegetation since the spring of 2016 to the autumn of 2017. In the soil layer of 0-30 cm there was a decrease of the Cox stock in the soil by 58.2 t·ha-1, the stock of Nt in the soil did not change. At the same location and during the same period, the Cox stock of 35,3 t·ha-1 and the Nt stock of 0,1 t·ha-1 fell on the restored vegetation in the soil layer of 0-30 cm. In the clay loam soil in Kladruby n.L. since the spring of 2017 to autumn 2017 there was a decrease of 27,6 t·ha-1 Cox and 1,4 t·ha-1 Nt in soil layer 0-30 cm on the restored vegetation. In the original vegetation, the Cox content decreased by 16.3 t · ha-1 and Nt by 0.4 t·ha-1. In the Oldřichovice over the house area, since the autumn of 2016 to the spring of 2018, the Cox stock fell after plowing in the soil layer 0-30 cm by 7 t·ha-1 and the Nt supply increased by 0.9 t·ha-1. In the Oldřichovice area under the hill, the Cox stock decreased by 39.2 t·ha-1 in the same period and in the same soil layer and the Nt stock decreased by 1.5 t·ha-1. From the point of view of the depth of soil, the largest amounts of organic carbon and total nitrogen in the upper layer of soil were recorded 0-10 cm. The C:N ratio in the restored and natural grasslands was not statistically different. At the same time, after the recovery in this layer of soil, the biggest loss of Cox and Nt occurred.
|
|
|
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.
|
|
|
Concentration of organic carbon in mountain and submountain watercourses
Špringerová, Pavla ; Matoušková, Milada (advisor) ; Havlíková, Petra (referee)
Bachelor thesis in its theoretical part is focused on the literature study of changes in concentrations of organic carbon in surface waters. The important part is finding the causes and consequences of these changes that could have a big impact on the entire global ecosystems. Uniform mechanisms controlling the process of increasing the concentration of organic carbon is not clearly defined yet, and therefore in the prediction of future consequences there exist disagreements. The practical part is devoted to research in experimental basins of the Department of Physical Geography and Geoecology (KFGG) of Faculty of Science, Charles University in Prague in the Otava river basin (central part of Šumava and upper basin of Blanice). The research was based on field survey of the area, water sampling and measurements of basic physical-chemical parameters. Samples of water, taken in several campaigns, were then analyzed in laboratory for determination of organic carbon in each sampling profiles. Simultaneously the preparation and processing of other data of KFGG from experimental basins took a place, focusing especially on rainfall-runoff process. This data has been linked to the measured values of organic carbon. Research results show a strong dependence of organic carbon concentration on precipitations...
|
|
|
Comparison of organic carbon stocks in soils with different land use
Rašková, Renáta ; Borůvka, Luboš (advisor) ; Tomáš, Tomáš (referee)
The aim of this thesis was to determine and compare the carbon stocks in selected locations.
Three localities were selected in Vyškov region. In each locality four types of soil according to their use were examined - forest, arable land, grass land and urban soil. From each type of soil four samples were taken which were located 10 meters from each other. Samples were taken by soil auger from 0 to 40 cm depth in November 2015. All samples were dried, ground and sieved. Consequently humus content was determined in samples by the Tyurin method. From these results content and stocks of organic carbon were calculated in each locality and each type of land use and all results were compared with each other.
Contribution of this thesis was to confirm or disprove hypothesis and to provide helpful information on Vyškov region.
Hypothesis: The stock of carbon in forest soil is higher than in arable land. The stock of carbon in arable land is higher than in urban soils.
The highest content of SOC was in forest soils and the highest stock of organic carbon was in arable land. Results show that the stock of carbon in soil is affected by land use and also by the way of management.
|
|
| |
guest ::
