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Assessing short rotation coppice poplar biomass and its determinants on former arable land in Czech Republic
Tripathi, Abhishek Mani
Forest coppice biomass, fast growing short rotation coppice (SRC) trees such as willows (Salix) and poplar (Populus) have a substantial potential of storing carbon (C), and has been considered as a sustainable source of woody dry mass. Woody dry mass production, energy efficiency and economic profitability of poplar are important and essential to be studied in Czech Republic. The aim of this PhD thesis was to predict standing woody dry mass, maximize the productivity and quantify the determinants of poplar clone J-105 (Populus nigra × P. maximowiczii) under short rotation coppice (SRC) management on former arable in Czech Republic. This PhD study was carried out in Domanínek, Czech Republic (49°31´N, 16°14´E and 530 m a.s.l.). Plantations were established in high density (9,216 trees ha-1) with single stem hardwood cuttings for verification purposes and to test the performance of poplar clone J-105 on former arable land. The plantations were harvested above 15-20 cm from base in winter 2008/2009 (established in April 2001) and 2009/2010 (established in April 2002). In this thesis, short rotation woody coppice (SRWC) plantations are mentioned as SRWC1 (coppice established in 2009) and SRWC2 (coppice established in 2010), respectively. In spring 2009, SRWC1 was divided into four randomized blocks and treated with three different fertilizers such as minerals [Nitrogen (N), Phosphorus (P), and Potassium (K)], sewage sludge and ash, lime and control (without any treatment of fertilizer). In the plantation SRWC2, no further (at beginning of second rotation-coppice) fertilizer treatment was applied. For the prediction of standing aboveground woody dry mass (AGWDM) in fertilizer treatments and control, allometric equations were developed. The allometric equations thus developed may be considered robust and site specific for poplar clone J-105. After the successful development of allometric equations standing annual AGWDM was estimated followed by annual inventory at the end of each growing season. There were no significant differences observed in allometric equations for AGWDM among the fertilizer treatments (including control) within the year over four years of study from 2011-2014. This experiment was repeated in plantation SRWC2, for which the allometric equation was developed separately, for the purpose of allocation of the aboveground and belowground woody dry mass (BGWDM) at the same site. In this plantation for estimation of AGWDM, allometric equation was developed in 2011 (after two years of plant growth in coppice) and for BGWDM, the equation was developed in 2014 (after more than four years of plant growth in coppice). In SRWC2 plantation, dynamics of annual and cumulative above and belowground woody dry mass were estimated over four years from 2011-2014, where average AGWDM were observed from 8.29 to 11.02 t ha-1 year-1 and average annual BGWDM varied between 2.50 to 3.02 t ha-1 year-1. Growth and wood production mainly depend on photosynthetic area and light efficiency. Therefore, leaf area development including leaf area index (LAI) and leaf area duration (LAD) and radiation use efficiency (RUE) was studied to find a suitable determinant for aboveground woody dry mass production. In the results, maximum leaf area index LAImax was observed to be 9.5 after four years of plant growth in coppice, maximum number of LAD was 185 days after two years of plant growth in coppice and maximum RUE was observed to be 1.3 gMJ-1 in GS4 (growing season four) after four years of plant growth in coppice. LAI and LAD showed a strong positive correlation for AGWDM (R2 values ~1) while RUE showed a moderate positive correlation with AGWDM, where R2=0.50 (p=0.52). This implies that AGWDM is strongly dependent on LAI and LAD. To conclude a robust and site specific allometric equation was developed for poplar clone J-105 and also, this study confirmed that, there was no significant impact of fertilizers for maximizing the AGWDM production on former arable land. For determinants of AGWDM, it confirmed that LAI, LAD and RUE could be a good and reliable predictor of standing AGWDM in SRC poplar clone J-105 on former arable land.
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Effect of fertilization of permanent grassland on the substrate biogas yield
Stibůrek, Jakub ; Fuksa, Pavel (advisor) ; Jiří, Jiří (referee)
The aim of this study was to extend knowledge about the influence of permanent grassland fertilization on the yield and the quality of biogas.
During the years 2013 and 2014 three levels of fertilization (non fertilized control, N50PK, N200PK) were tested. Samples were taken from the experiment site Černíkovice, Benešov region. For anaerobic digestion, a 40 day mesophilic conditions batch test was chosen.
A statistically significant decrease of substrate biogas yield (SBY) and area biogas yield (ABY) with higher doses of fertilizers occurred between non fertilized control (575.4 ml/g; 3332.4 m3/ha) and N200PK variant (460.5 ml/g; 2605.7 m3/ha) in 2013. The only statistically significant differences in the quality of biogas were found during the first day of anaerobic digestion, when the highest doses of fertilizers caused higher concentration of methane (33.2 %) compared to control variant (22.6 %).
Application of fertilizers had no significant effect on SBY in 2014. Still, the highest SBY was obtained from the non fertilized control (762.7 ml/g) compared to N50PK (707.6 ml/g) and N200PK variant (732.8 ml/g). Furthermore, significant most of the ABY was obtained from the N50PK (2911.5 m3/ha) compared to the non fertilized control (2296.3 m3/ha). The only significant differences in biogas quality were found during the initial 7 days of the test. Most of the methane was contained in biogas from the non fertilized control (59.1 %), and least amount of the methane was found in the N50PK variant (57.9 %).
ABY is highly influenced by the yields of phytomass, which were negatively affected by the late first cut caused by unfavorable site conditions in 2013.
Cumulative biogas production showed that the most important part of anaerobic digestion was during the initial 14 days, which produced upwards of 80 % of total biogas yields in both years.
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System analysis of agriculture enterprise on bioenergy production in foothills
HAMBERGEROVÁ, Jana
Chosen agricultural enterprise Agricultural-Trading Cooperative Farm operates 20 km away from České Budějovice in South Bohemia Region. Analysis of inner structure of this farm was performed for period 1997 {--} 2006. To project inner structure of the agricultural system, it is necessary to know the harvest area and yield of individual crops, cattle stock, and mineral fertilizer consumption. On the basis of performed analysis, using carbon-balance method, projects of inner structure specialized in bioenergy production were calculated. The production of bioethanol from cereals, oil from rape and biogas from cattle breeding refuse are taken into account. At comparison of individual variants from aspect of energetic gain under existing natural conditions, the variant specialized in cereals for ethanol production proves as the most suitable.
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System analysis of chosen agricultural farm at higher location at orientation on bioenergy production
ŠIMEK, Michal
Chosen agricultural enterprise Agricultural Cooperative Slapy u Tábora farms in the South Bohemia Region near the Tábor city. Analysis of inner structure of this farm was worked out for the period 1996 {--} 2006. Harvest area and yield of individual crops, mineral fertilizer consumption and cattle stock have been used for the analysis. On the basis of performed analysis, variants of inner structure have been calculated, aimed on production of bioenergy: cereals for bioethanol production, raps for biodiesel production, biogas. From aspect of energetic gain, the variant for bioethanol production was evaluated as optimal.
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Bioenergy as an Alternative Source of Fuels for Transport in World Economics
Běláčková, Adéla ; Vošta, Milan (advisor) ; Kašpar, Václav (referee)
Práce pojednává o využívání bioenergie jako obnovitelného a environmentálně šetrného paliva pro dopravu. Zabývá se otázkou schopnosti biopaliv postupně nahradit ropná paliva v dopravě a snížit tak emise skleníkových plynů i energetickou závislost dopravy na nabídce ropy. Hodnocenými biopalivy jsou bioetanol, biodiesel a bioplyn. Hodnotícími faktory potom environmentální přínosy spojené s jejich využíváním, cenová konkurenceschopnost a odhadované produkční kapacity. Práce vychází především ze zkušeností získaných v zemích Západní Evropy, USA a Brazílii.
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