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Growth rate of dominant cyanobacteria with different strategies from pond ecosystems
SYSLOVÁ, Petra
The thesis deals with fast growing unicellular cyanobacteria (Synechocystis sp. PCC 6803 and Cyanobium gracile A1) and slower growing filamentous cyanobacteria capable of fixing atmospheric nitrogen (Anabaena lemmermannii, Anabaena compacta and Anabaena reniformis). The experiment was designed to observe the growth of selected representatives from both these types at different temperatures in media with different concentrations of nitrogen. Growth was measured using on optical density at a wavelength of 550 nm. The results from the individual measurements were graphically evaluated using growth curves. The cell size and cell volumes of each strain were also determined. It was concluded that at higher temperature and at higher nitrogen concentrations, most of the cyanobacteria showed higher growth. It can be concluded that during the summer period, in our ponds with sufficient nitrogen, these cyanobacteria will readily increase their biomass and thus influence pond management.
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Souvislost změn v cyklech dusíku a uhlíku v lesních půdách po odumření stromového patra
TUPÁ, Adéla
The bachelor's thesis deals with changes in nitrogen and carbon cycles in coniferous forest soils after tree layer dieback due to forest disturbance. The thesis focuses on changes in nitrification and availability of nitrates in soils in connection with microbial biomass and carbon availability, especially in the forests with non-intervention management. This thesis contains of two parts, a literature review, and a scientific project proposal, which aims to verify possible validity of heterotrophic-competition hypothesis of microbes in soils.
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Winter wheat growing in terms of selected farms
PAUL, Radim
The goal of the bachelor thesis was to establish and evaluate a pilot experiment. The effect of 3 nutritional variants with a graded dosage of nitrogen and the application of a growth regulator with the active substance trinexapac-ethyl on the yield and quality parameters of winter wheat grain was evaluated. There was 145 kg pure nutrient N*ha-1 of growth regulator in scenario 1, 191 kg pure nutrient N*ha-1 in scenario 2 and 191 kg pure nutrient N*ha-1 with applied growth regulator in scenario 3. The experiment was performed on a family farm in the growing season of the year 2018 and 2019 near the village Dobkov by the town Chotěboř. The actual yield was in scenarios 2 and 3 was only slightly increased (in the order of tens of kilograms) in spite of the higher dosage of nitrogen in scenario 2 and the application of a growth regulator in scenario 3. Both the higher dosage of nitrogen and the addition of growth regulator had a positive effect on yield-forming elements, and increased the number of ears per m2, further reducing the average number of grains in a spike in scenarios 2 and 3. The weight of one thousand grains was positively affected by a higher dosage of nitrogen in scenario 2, but negatively affected in scenario 3. All quality parameters (nitrogen content, gluten content, Zeleny test and bulk mass) were positively affected by a higher dosage of nitrogen in scenario 2. The application of the growth regulator in scenario 3 increased the declining trend, the Zeleny test, the gluten content, the nitrogen content and also negatively affected the bulk mass.
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Možnosti zachycení a recyklace živin při vypouštění rybníků
DOFEK, Jan
This diploma thesis tries to verify the possibilities of effective retention of sediments and nutrients from the run-off water during harvesting of ponds. Retention was tested using a system of two barriers made of organic material looking to temporarily count down water in the drains and extend the water residence time to sediment the particles. Monitoring of water quality was demonstrated on eight ponds in the South Bohemian Region, which manages fisheries company the Blatenská ryba, s.r.o. The following parameters were monitored: Undissolved substances 105; 550, total and dissolved phosphorus, total nitrogen, total carbon, total organic carbon, BOD5, CODCr, calcium, magnesium, potassium, large iron and dissolved. Water samles were processed in the laboratories of the state enterprise Povodí Vltavy in České Budějovice. Evaluation of results based on the evaluation of nutrient content in water and sediment samples on the profile under the dam (profile A) and under the other barrier (profile B). The flow of water over two hundred barriers increased the water quality. There was a statistical decrease earlier in all monitored parameters. The difference between the values of the values on profile A under the pond and under the other barrier (profile B) was not confirmed only in Fedissolve and at Pdissolve., at any time to increase their concentration. During the discharge of water from the pond and during the actual fishing of water to increase all monitored parameters. The highest values of concentrations were found at the end of BOD5, US105, US550, Fe and Fedissolve. The highest values during fishing are caused by the active movement of fish, people in catch basin.and with the crawling of fish, the pulling of the net, the lifting of the roofs of the net and the core. By flowing through the barriers, the concentration in the effluent water was reduced by up to 50%. Retention of up to 90% was possible for individual parameters (TP). According to these experiences, the efforts of operators should be to capture nutrients, especially from the start of fishing to the start of discharge and stopping the outflow of water, when it is possible to significantly eliminate their leakage into the basin. On average, 9,834 kg.ha-1 of sediment (in the raw state) was published. In this amount of sediment, 1015.89 kg of total nitrogen (22.3 kg.ha-1), 206.04 kg of total phosphorus (4.47 kg.ha-1), 294.11 kg of potassium (6.56 kg.ha-1), 1,097.92 kg calcium (23.58 kg.ha-1) and 10,108.63 kg received (220.69 kg.ha-1). The perceived sediment contained an average of 4.47 kg.ha-1 phosphorus. Dissolved phosphorus is a key parameter in the problem of eutrophication. The results of the water do not show that the catch of the pond is not such a serious problem in terms of dissolved phosphorus. During catches, the bound form of phosphorus predominated, with a share of 99%. The results, according to the objectives, can be used to capture the technology of sedimentation and nutrients in the run-off water when fishing ponds. Barriers made of organic material are able to retain and sediment nutrients from running water from ponds. This makes it possible to improve the quality of water discharge when fishing for ponds.
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Reaction of selected potato varieties to single and split application of nitrogen
MICHALÍČEK, David
The aim of the bachelor thesis is to evaluate the response of varieties with different lengths of vegetation to single and divided doses of nitrogen in potato growing. To point out the effect of nitrogen on tuber yield. The results of the experiment also consider the technology of cultivation, treatment and conditions during the vegetation. The work also records individual differences between varieties and starchy of tubers. The experiment was performed on a plot of land near Havlíčkův Brod near the experimental station in Valečov. Two variants of varieties with different vegetation times were selected for the experiment. The plot was divided into three variants of nitrogen application in three replicates. In the first variant, which was not fertilized with nitrogen, there was no high yield, but in the second variant, which was fertilized with nitrogen before and during vegetation, and in the third variant with fertilization before vegetation, the increase in yield was noticeable for selected varieties. At the same time, there were different values in determining the proportion of starch in tubers.
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Současný stav kvality vody v rybnících
BENEDIKT, Adam
Monitoring the quality of water in a pond in connection with fisheries management did not begin to gain importance until the end of the 20th century. Since then, numerous studies have been conducted on this topic. Currently, the most significant problem affecting not only the fishing companies is the eutrophication and its impact on the function of a pond and the surrounding landscape (including biodiversity and the overall impact of eutrophication on the environment). Anthropogenic activity (e.g., fish farming, wastewater, and agriculture) leads to an excessive release of mineral nutrients, predominately phosphorus and nitrogen, into open waters. This bachelor thesis compares the data obtained from measurements from the year 2017 with data from the 1950s. until 2014 as documented in the written records. The actual data represent the basic physicochemical parameters of water (i.e., temperature, O2 concentration, pH, conductivity and ORP, TN, NH4-N, NO3-N, TP, DRP, TOC, and chlorophyll-a). The evaluation is based on a collection of data from six ponds in the vicinity of České Budějovice (Beranov, Roubíček, Zběhov, Posměch, Kvítkovice, and Dehtář) with a representation of production and fry tanks.
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Jak se mění kvalita vody na odtoku z rybníků při jejich výlovu
VÁGNER, Martin
The goal of this diploma thesis was to characterise the change of pond effluent quality during fish harvesting period. The change of water quality variables were measured and the pond draining stage at which fish harvesting activities affect most the quality of pond effluent was identified. Results and observations should help with the development of technology for retaining the sediment and nutrients discharged from ponds during fish harvest. The monitoring of pond effluent quality was carried out in twelve ponds managed by Krajské školní hospodářství České Budějovice in South Bohemian region. At different fish harvest phases, water temperature, concentration of dissolved oxygen, conductivity, turbidity and pH were measured in situ with a multiparametric probe YSI EXO 2. At the same time, water samples were also taken to quantify the concentration of suspended solids (SS), total phosphorus (TP), particulate and dissolved phosphorus (PP, DP) and total nitrogen (TN). Water samples were processed in the laboratories of the state enterprise Povodí Vltavy in České Budějovice. Our results confirmed that draining and fish harvest have significant influence on the quality of both the pond effluents and probably on the water bodies located downstream of the ponds. The largest changes of monitored parameters were caused by the time of active movement of fish and people in fish harvesting area. The active movements include setting the tanks for fish sorting, fish scaring, and seining. The highest concentrations of suspended solids, total phosphorus and total nitrogen were detected at the stage of catching fish with hand nets and surface outflow after the end of fish harvest. The changes of values during the fish harvest were considerable (% higher than pond water) and was fast. Therefore, best management practices aiming at reducing the concentration of SS, TP and TN may be implemented starting from the stage of fish netting until the closure of the pond outlet. Dissolved phosphorus has been identified as the key parameter causing eutrophication. The results of our study revealed that fish harvest is not so important problem from this point of view. During fish harvests obviously dominated particulated phosphorus which part was in average more than 99 %. The quality of effluent discharged during fish harvest was mainly influenced by the biomass and type of fish. Weather, water level regulation and type of outlet device influenced the effluent quality as well but at a lesser extent.
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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.
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Vulnerability of organic matter in permafrost-affected soils and potential greenhouse gas emissions
DIÁKOVÁ, Kateřina
Degradability of soil organic carbon and potential greenhouse gas emissions were studied in permafrost-affected soils. Special attention was paid to cryoturbated horizons in upland tundra and cryogenic bare ground features exposing deep peat layers on a surface of permafrost peatland. The presented studies aimed to identify driving factors influencing degradability of organic carbon in arctic soils and the effects of temperature, oxygen availability and addition of plant-derived organic compounds were targeted by several laboratory incubation experiments. Role of nitrogen availability in C cycling and GHGs production was further investigated in combination of field measurements and laboratory experiments.
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Storing of manure, treated sludge and feed on agricultural land
Svoboda, Pavel ; Wollnerová, Jana ; Kozlovská, Lada ; Klír, Jan
Solid manure of various livestock, compost and, more recently, digestate separates may be deposited on agricultural land under certain conditions. The rules for their imposition are laid down by legislation. The methods of storing treated sludge and voluminous fodder, such as silage and hay, and the operation of feeding grounds on agricultural land are also determined by current legislation. Of the mineral fertilizers, it is possible to deposit on agricultural land only the calcium fertilizer (sugar bowl, fertilizers based on ground limestone). The methodology responds to the changes in legislation in 2020 and 2021, is based, among other things, on agricultural practice and provides comprehensive guidance for storing these materials and operating feeding grounds on agricultural land. It clearly describes all measures aimed at maintaining the quality of the material stored and reducing the risk of environmental pollution, in particular surface water and groundwater. It also recommends the possibility of reclamation after delivery of fertilizers, treated sludge, removal of feed and closure of the feeding grounds. Particular attention shall be paid to measures addressing the potential of sites in vulnerable areas identified under the Nitrates Directive Action Programme. Last but not least, the methodology also includes instructions for selecting a suitable place to store fertilisers, treated sludge and voluminous feed, or a place to feed, using data from the Land Register (LPIS) at the Farmer's Portal.
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