No description available.

The increasing U.S. dependence on imported oil; the contribution of fossil fuels to the greenhouse gas emissions and the climate change issue; the current level of energy prices and other environmental concerns have increased world interest in renewable energy sources. Biomass is a large, diverse, readily exploitable resource. This dissertation examines the biomass potential in Eastern Texas by examining a 44 county region. This examination considers the potential establishment of a 100-megawatt (MW) power plant and a 20 million gallon per year (MMGY) ethanol plant using lignocellulosic biomass. The biomass sources considered are switchgrass, sugarcane bagasse, and logging residues. In the case of electricity generation, co-firing scenarios are also investigated. The research analyzes the key indicators involved with economic costs and benefits, environmental and social impacts. The bioenergy production possibilities considered here were biofeedstock supported electric power and cellulosic ethanol production. The results were integrated into a comprehensive set of information that addresses the effects of biomass energy development in the region. The analysis indicates that none of the counties in East Texas have sufficient biomass to individually sustain either a 100% biomass fired power plant or the cellulosic ethanol plant. Such plants would only be feasible at the regional level. Co-firing biomass with coal, however, does provide a most attractive alternative for the study region. The results indicate further that basing the decision solely on economics of feedstock availability and costs would suggest that bioenergy, as a renewable energy, is not a viable energy alternative. Accounting for some environmental and social benefits accruing to the region from bioenergy production together with the feedstock economics, however, suggests that government subsidies, up to the amount of accruing benefits, could make the bioenergies an attractive business opportunity for local farmers and investors.

Like many large cities, Johannesburg faces several sustainability challenges such as unsustainable use of natural resources, emissions contributing to environmental- and waste related problems. The city is a provincial transport centre, and the transport sector is responsible for a large share of the city’s energy demand and emissions. To approach several of these challenges simultaneously the City of Johannesburg considers the possibilities to use renewable, waste-based, fuel for public transport and has shown a great interest in how Sweden produce and use biogas.  In this study an early assessment of the potential, feasibility, economic costs and environmental performance of a waste-based biomethane solution in Johannesburg is performed, with the purpose to fuel a public transport bus fleet. This has been done by developing and using a multi-criteria analysis (MCA). The MCA consists of four categories: potential, feasibility, economic costs and environmental performance. These categories consist of 17 key areas with corresponding key questions and indicators with relating scales used for scoring the indicators. The indicators and scales help identify what information is necessary to collect for the assessment. Furthermore, an Excel tool and a questionnaire are provided to serve as a help when performing the assessment. The feasibility assessment is conducted both for the city as a whole as well as for individual feedstocks. Information for the studied case was gathered from a literature study and interviews in Johannesburg with local experts and potential stakeholders.  The identified feedstocks in Johannesburg are landfill gas, waste from a fruit and vegetable market, organic household waste, abattoir waste, waste from the food industry, waste management companies and sewage sludge from the wastewater treatment plants (WWTP). The identified biomass potential is 230,000 tonnes of dry matter/year, generating a total biomethane potential of 91,600,000 Nm3/year, which is enough to fuel almost 2700 buses. In the process of producing biogas, digestate is created. The digestate can be used as biofertilizer and recycle nutrients when used in agriculture. The complete biomass potential in Johannesburg was not identified meaning there is additional potential, from e.g. other food industries, than examined in this study.  Assuming that all feedstocks except for landfill gas and WWTP sludge are processed in one biogas plant, the investment cost for this biogas plant is 28 million USD and the total operation and maintenance cost is 1.4 million USD per year. The investment cost and yearly operating cost for the upgrading plant is 43 million USD and 2.4 million USD respectively. Finally, the distribution costs were calculated, including compression and investment in vessels. The investment and operational costs for compression is 7.4 million USD and 220,000 USD/year respectively. The investment cost for the vessels was calculated to 15 million USD and the operational costs of the distribution 16 million USD/year. Consideration should be given to the fact that the numbers used when calculating these costs comes with uncertainties. Most indicators in the feasibility assessment of the city as a whole were given the score Poor, but some indicators were scored Satisfactory or Good. The assessment of the individual feedstocks led to a ranking of the most to the least feasible feedstocks where the waste from the fruit and vegetable market and the municipal household waste are considered being in the top. This assessment also shows the feedstocks are in general quite suitable for biomethane production. The issue is the lack of economic and legislative support and strategies not working in favour of biomethane. These are areas that can be improved by the local or national government to give better conditions for production of biomethane in the future. Some examples of this are a proposed landfill tax or landfill ban as well as a closing of the landfills due to the lack of new land. This could all contribute to better conditions for biomethane solutions in the future. Main identified hinders are electricity generation from biogas as a competitor with biomethane, and a general lack of knowledge about biogas and biomethane, from the high-level decision makers to a workforce lacking skills about construction and operation of biogas plants.

Production of biogas through anaerobic digestion is one pathway to achieving the European Union (EU) goals of reducing greenhouse gas emissions, increasing the share of renewable energy, and improving energy efficiency. In this thesis, two different models (Anaerobic Digestion Model No. 1 and an artificial neural network) are used to simulate a full-scale co-digester in order to evaluate the feasibility of such models. This thesis also includes models of two systems to study the inclusion of microalgae in biogas plants and wastewater treatment plants. One of the studies is a life-cycle assessment in which replacement of the ley crop with microalgae is evaluated. The other study concerns the inclusion of microalgae in case studies of biological treatment in three wastewater treatment plants. Finally, the co-digestion between microalgae and sewage sludge has been simulated to evaluate the effect on biogas and methane yield. The results showed that Anaerobic Digestion Model No.1 and the artificial neural network are suitable for replicating the dynamics of a full-scale co-digestion plant. For the tested period, the artificial neural network showed a better fit for biogas and methane content than the Anaerobic Digestion Model No. 1. Simulations showed that co-digestion with microalgae tended to reduce biomethane production. However, this depended on the species and biodegradability of the microalgae. The results also showed that inclusion of microalgae could decrease carbon dioxide emissions in both types of plants and decrease the energy demand of the studied wastewater treatment plants. The extent of the decrease in the wastewater treatment plants depended on surface volume. In the biogas plant, the inclusion of microalgae led to a lower net energy ratio for the methane compared to when using ley crop silage. Both studies show that microalgae cultivation is best suited for use in summer in the northern climate.

Biofuels produced from forest residues are much discussed in a Swedish context, among other things due to concerns for climate change. However, the undertaking of climate performance calculations is not an exact science. To examine whether climate concerns may be met by biofuels produced from forest residues, a literature review was carried out, analysing studies across methodologies. The scope for the literature review was limited to climate performance calculations for biofuels produced from forest residues harvested in Sweden. Five articles have been chosen for presentation, whereof one was carried out according to ISO 14040:2006 methodology, two according to climate performance calculations as stipulated by RED, two according to cumulative radiative forcing (CRF) and one according to a bottom up model using data from demo plants in Sweden (one study covers both ISO and RED methodology). All five studies presented in this paper suggest that climate performance of biofuels produced from forest residue (harvested in Sweden) show significantly better climate performance than fossil fuels. The local, environmental effects as well as future potential for harvesting of forest residue were also explored. A synthesis report on local, environmental effects suggests that the local, environmental effects are small. Furthermore, it is concludes that the effects on SOC are minor. Lastly, it is suggested that there is potential of increased harvesting of forest residue in Sweden in the magnitude of 30 TWh. / Biobränslen producerade av skogsavfall diskuteras mycket i en svensk kontext. Eftersom beräkningar av klimatprestanda inte är en exakt vetenskap, utfördes en litteraturstudie för att undersöka utifall biobränslen producerade från skogsavfall kan uppfylla förväntad klimatprestanda. Litteraturstudien avgränsades till beräkningar av klimatprestanda för biobränslen producerade av svenskt skogsavfall. Fem artiklar valdes ut, varav en använde sig av ISO 14040:2006 metodologi, två utfördes enligt RED, två enligt strålningsberäkningar och slutligen en som använt sig av data från demo fabriker i Sverige. Alla fem studierna visar att biobränslen producerade från svenskt skogsavfall har signifikant bättre klimatprestanda i jämförelse med fossila bränslen. De lokala miljömässiga effekterna samt framtida potential undersöktes. En syntesrapport drog slutsatsen att de lokala miljömässiga effekterna var små. Vidare, drogs slutsatsen i en annan rapport att effekterna på kol i marken var små. Slutligen uppskattades den framtida öka potentialen av ett ökat uttag av skogsbränsle till ca 30TWh per år.

För att Sverige ska nå klimatmålet om noll nettoutsläpp av växthusgaser till år 2045 behöver bland annat mer biobränslen fasas in och fossila bränslen fasas ut och därför behövs större produktion och fler alternativ av biobränslen. Pyrolysolja är ett alternativ till biobränsle som har forskats på sedan 1970-talet men som först för några år sedan börjat produceras i större skala för användning till värmeproduktion. Först i år startades även en byggnation för produktion av pyrolysolja som ska uppgraderas till biodrivmedel av Pyrocell. Pyrolysoljan har annorlunda egenskaper och sammansättning mot andra biooljor och fossila oljor. Till exempel har pyrolysolja högt vatteninnehåll, hög viskositet och högt innehåll av syresatta komponenter vilket gör att pyrolysoljan har lågt värmevärde, är svårare att hantera och är ostabil. Karlstad Energi AB har påbörjat ett projekt för att utvärdera en integrerad pyrolysreaktor vid en befintlig kraftvärmepanna med målsättningen att i framtiden producera pyrolysolja. De är intresserade av att använda pyrolysoljan som bränsle i två av deras reservpannor för fjärrvärmeproduktion och för att få produktionen lönsam är de dessutom intresserade av att sälja pyrolysoljan som råvara till drivmedelsindustrin. Syftet med arbetet är att undersöka pyrolysoljans användbarhet i Karlstad Energis system utifrån pyrolysoljans egenskaper, åldring, förbränning och uppgradering till biodrivmedel samt jämföra pyrolysoljans egenskaper och förbränning med biobränslet de använder idag, bio100. Målen är att; (1) kartlägga och jämföra pyrolysoljans egenskaper med bio100 utifrån litteratur, (2) beräkna och bedöma viskositetsförändring samt varmhållnings och förvärmningstemperaturer av färsk och lagrad pyrolysolja utifrån litteratur, (3) beräkna förbränningsegenskaper och förbränningsprestanda vid en uttagen effekt på 30 MW i reservpannan genom simulering i Chemcad tillsammans med en uppbyggd värmeöverföringsmodell i Excel och (4) undersöka möjligheten att uppgradera pyrolysolja till biodrivmedel genom teoretisk beräkning av vätgasbehov och oljeutbyte. Pyrolysoljan undersöks med 25, 15 och 8 vikt % vatten och tillsats av 5 och 10 vikt % metanol och etanol för att stabilisera pyrolysoljan samt förbättra förbränningen. Resultaten visar på att en pyrolysolja med 8 % vatteninnehåll kan ha alltför hög viskositet för att kunna pumpas och förbrännas i rimliga varmhållnings- och förvärmningstemperaturer, medan 26 och 15 % klarar det med rimliga temperaturer, med och utan tillsats av alkohol. Vid förbränning med en uttagen effekt på 30 MW krävs ca 1,9-2,6 gånger så högt oljeflöde och ca 1,05-1,21 gånger så högt rökgasflöde för pyrolysoljorna mot bio100 (3250 kg/h respektive 42900 m3/h). Det innebär att anläggningen skulle kunna vara underdimensionerad för att få ut 30 MW vid förbränning av pyrolysolja där oljeflödet förmodligen är det begränsande flödet. Detta kräver ytterligare utredning av utrustningen. Luft-bränsle förhållandet för att uppnå 4 % syreöverskott är ca dubbelt så stort för bio100 mot pyrolysoljorna (16 mot 6,7-8,6 kg luft/kg olja). Utsläpp av stoft och NOx kan bli väldigt högt på grund av det höga ask- och kväveinnehållet och kommer förmodligen inte klara de framtida utsläppsbegränsningarna varav åtgärder kommer behövas. Verkningsgraden (baserat på det högre värmevärdet) för 8 % vatteninnehåll med 10 % etanol kommer upp i samma verkningsgrad som bio100 (91 %) mot 26 och 15 % vatteninnehåll som kommer upp i ca 84 respektive 88 %. Det teoretiskt beräknade vätgasbehovet och oljeutbytet ligger mellan ca 575-775 liter vätgas/kg pyrolysolja respektive ca 45-62 %. Överlag är tillsats av metanol det bättre alternativet för viskositeten men etanol är bättre vid förbränning och uppgradering till biodrivmedel. / For Sweden to reach the goal of zero net emissions of greenhouse gases by the year 2045, more use of biofuels and less use of fossil fuels is needed and for this we need higher production and more options of biofuels. One option is pyrolysis oil which has been in research since the 1970’s but was only recently introduced to large-scale heat production. Also, this year Pyrocell have started the construction of a pyrolysis plant where the pyrolysis oil is going to be upgraded to biofuels. The pyrolysis oil has different properties and composition compared to other biooils and fossil oils. For example, it has high water content, high viscosity and high content of oxygenated compounds which makes the oil more difficult to handle, unstable and gives the oil a low heating value. Karlstads Energi AB has started a project to evaluate an integrated pyrolysis reactor to one of their existing combined heat and power plants with the objective to produce pyrolysis oil in the future. They are interested in using the pyrolysis oil as a fuel in two of their reserve boilers for district heating production and to sell as raw material to the fuel industry. The object of this study is to investigate the possibility of using the pyrolysis oil at Karlstads Energi in the meaning of properties, aging, combustion and upgrading to biofuel and to compare the properties and combustion performance with the fuel they are using today, bio100. The goals are to; (1) map and compare the properties and composition of pyrolysis oil with bio100 from literature, (2) calculate and estimate changes of viscosity and storage- and atomization temperatures of fresh and stored pyrolysis oil using data from literature, (3) calculate combustion properties and combustion performance at 30 MW power outlet from the boiler through simulation in Chemcad and a heat transfer-model in Excel and (4) investigate the possibility to upgrade pyrolysis oil to biofuel through theoretical calculation of hydrogen consumption and biofuel yield. The pyrolysis oil is investigated with 25, 15 and 8 wt% water and addition of 5 and 10 wt% methanol and ethanol to stabilize the oil and to improve the combustion. The results shows that a pyrolysis oil with 8 wt% water could have too high viscosity to be able to be pumped and combusted in reasonable temperatures while 26 and 15 wt% water have lower viscosity and can be used in reasonable temperatures, both with and without addition of alcohol. At combustion with 30 MW power output the flow of pyrolysis oil and flue gases is 1,9-2,6 times and 1,05-1,21 times higher than bio100, respectively (3250 kg/h and 42900 m3/h, respectively for bio100). This means that the facility could be undersized to be able to get 30 MW power output with pyrolysis oil, where the oil flow probably is the limiting factor. This requires further investigation of the equipment. The air-fuel-ratio to receive 4% excess oxygen in the flue gases for the pyrolysis oils is about half of that of bio100 (6,7-8,6 compared to 16 kg air/kg oil, respectively). The emissions of dust and NOx are high for the pyrolysis oils because of high content of ash and nitrogen and will probably exceed the future limitations of which measures will be needed. The efficiency (based on higher heating value) for pyrolysis oil with 8 wt% water and 10 wt% ethanol can reach the same efficiency as bio100 (91%), while 26 and 15 wt% water content reach 84 and 88%, respectively. The theoretical hydrogen consumption and biofuel yield were calculated to 575-775 L hydrogen/kg pyrolysis oil and 45-62%, respectively. Overall, addition of methanol is a better choice for the viscosity, but ethanol performs better in combustion and upgrading to biofuels.

The depletion of fossil fuel resources, pollution concerns and the challenge of energy security are driving the search for renewable energy sources. The use of lignocellulosic plant biomass as an energy source is increasing in the United Kingdom and worldwide. In the UK, up to 0.35MHa (6% of total arable land) may be planted with perennial bioenergy crops by 2020 in order to meet renewable energy and CO2 reduction targets. Several plant species that produce high biomass from low inputs have been identified. The most promising for the UK climate are the genus Miscanthus, a perennial rhizomatous grass which can grow up to 3.5m in a year, and short rotation coppice (SRC) willow (Salix spp.), plantations of which can remain viable for up to 30 years. Although bioenergy crops are perceived as “carbon neutral”, changes in land use can have a wider impact on atmospheric composition than through CO2 alone. This study compares vegetation fluxes of methyl halides (CH3Br and CH3Cl) and biogenic volatile organic compounds (BVOCs) from perennial bioenergy crops and annual arable crops at three sites in the UK. Methyl halides are the most abundant natural vectors of bromine and chlorine into the stratosphere and play an important role in stratospheric ozone destruction. BVOCs affect atmospheric oxidising capacity and are a major precursor to the formation of ozone and secondary organic aerosols in the troposphere. Although terrestrial vegetation is an important source of these trace gases there are very few previous measurements of these reactive gases from bioenergy crops. This study describes measurements conducted at two SRC willow sites in Scotland, and one site in England planted with adjacent perennial bioenergy crops and annual arable crops, to quantify and characterise natural methyl halide and BVOC fluxes from vegetation. Measurements were conducted with branch chambers, using static enclosure techniques to measure methyl halide fluxes and dynamic enclosures to measure BVOCs such as isoprene and -pinene. Fluxes were calculated from the concentration difference between background/inlet samples and after enclosure/outlet samples. Methyl halide concentrations were determined by sampling gas from static enclosures followed by analysis using an oxygen-doped GC-ECD with a custom-built pre-concentration unit. Samples for BVOC analysis were collected onto adsorbent tubes and a thermal desorption GC-MS was used to determine BVOC concentrations. Potentially influential environmental variables such as photosynthetically active radiation (PAR), total solar radiation, air temperature, soil temperature, internal chamber temperature and soil moisture were recorded in parallel to the enclosures to determine their potential relationships to fluxes. Long-term environmental data was also available from on-site or nearby weather stations. Long-term measurements were carried out for 2 1 2 years at a site in Lincolnshire, England where adjacent fields are planted with Miscanthus, SRC willow and annual arable crops (wheat and oilseed rape crop rotation). Vegetation measurements were made almost every month throughout the period, with more intensive measurements such as full diurnal cycle carried out during the summer. Ten sampling points are sampled in each field and semi-diurnal measurements are taken regularly. Long-term measurements were also carried out at two sites in Scotland planted with SRC willow, one in Arnot, Perth & Kinross which was sampled for a year and one in East Grange, Fife which was sampled for half a year. Up to 30 sampling points were employed in Arnot and another 10 in East Grange. The bioenergy crops and wheat emitted low fluxes of methyl halides in comparison to the oilseed rape. Mean annual net fluxes of CH3Br and CH3Cl from Miscanthus were 1.8 ng g (dry weight)-1 h-1 and 11 ng g-1 h-1, respectively. At the three willow sites, mean annual net fluxes of CH3Br and CH3Cl ranged between 0.6 - 1.7 ng g-1 h-1, and 1.7 - 12 ng g-1 h-1, respectively. Negligible fluxes of methyl halides were measured from wheat but oilseed rape was found to emit large fluxes of methyl halides with mean annual net fluxes of CH3Br and CH3Cl of 20 ng g-1 h-1and 144 ng g-1 h-1, respectively. The largest BVOC fluxes were measured from SRC willow at the Brattleby site, with high mean annual net fluxes of isoprene (77 μ g g-1 h-1), α -pinene (46 g μg-1 h-1), β -pinene (5.5 μ g g-1 h-1), limonene (3.7 μ g g-1 h-1) and δ -3-carene (11 μ g g-1 h-1). However, mean annual net BVOC fluxes measured at Arnot and East Grange were much lower. High fluxes of - pinene were measured from Miscanthus in 2010 (giving a mean annual net flux of 65 μ g g-1 h-1) but no other significant BVOC fluxes were distinguished. Negligible fluxes of isoprene were measured from wheat but fluxes of monoterpenes were high with mean annual net fluxes of 65 μ g g-1 h-1 and 25 μg g-1 h-1 for α -pinene and limonene, respectively. No significant fluxes of BVOCs were measured from the oilseed rape. All fluxes demonstrated a strong seasonal trend with higher emissions during the summer growing season and low to zero emissions over winter. The high spatial variability was captured by sampling from many points in each field. Some diurnal measurements exhibited a clear pattern of higher emissions during the day and low to zero emissions at night. Some positive correlations between fluxes and environmental variables such as PAR and air temperature were observed. An experiment carried out on willow cuttings in the greenhouse found no clear increase or decrease in fluxes of BVOCs in response to N fertiliser treatment, instead fluxes were found to vary significantly with some of the observed environmental variables. UK estimates were derived by extrapolating measured fluxes using the current respective land cover areas for Miscanthus and SRC willow. Estimated UK annual fluxes of CH3Br and CH3Cl from Miscanthus were 0.01Mgy-1 and 0.05Mgy-1, respectively and from SRC willow were 0.06Mgy-1 and 0.4Mgy-1, respectively, accounting for a very small percentage of total global annual turnover of CH3Br and CH3Cl. Estimated UK annual fluxes of the BVOCs isoprene and α -pinene from Miscanthus were 0.01Mgy-1 and 0.4Mgy-1, respectively and from SRC willow were 3Mgy-1 and 1Mgy-1, respectively. Future planting of SRC willow to meet the UKs energy needs could lead to a potential annual isoprene flux of 150 MgMgy-1.

There is a growing need to reduce the use of fossil fuels for energy. A twofold reason exists for this: firstly these resources are finite; secondly the utilisation of these resources releases greenhouse gases which are known to contribute towards climate change. The rise in global population and energy use per person is adding to the unsustainable use of fossil fuels. There is the potential to reduce fossil fuel consumption in the South West of England. The region’s abundant natural resources could be used to reduce the overreliance on energy from fossil fuels. A key natural and renewable resource within the region is the availability of biomass. Bioenergy is a form of energy, derived from biomass. Bioenergy has the capability to displace the use of fossil fuels. Additionally, it has the potential to reduce the effect of climate change by absorbing carbon dioxide during the biomass production period. It has the possibility of being integrated into existing infrastructure and is one of the few renewable technologies which can satisfy an array of end-use energy requirements. This thesis highlights a unique method of assessing the potential of bioenergy in the South West of England using a multi appraisal technique. The initial assessment within this thesis has examined the resource availability of bioenergy based on biomass feedstock. Whilst quantifying the overall availability, constraints have been examined to determine the realisable potential of biomass as an energy source. The analysis has then assessed the drivers and barriers of bioenergy development within the region and contextualised this for the UK in general. Following the selection of a single bioenergy pathway (biogas production from anaerobic digestion), the technology has been assessed using a multi appraisal methodology. This methodology has involved the use of net-energy analysis, environmental life cycle assessment and financial investment assessments. The thesis demonstrates that the region has a notable resource availability of biomass. However, a number of barriers to development have been found which could impede the utilisation of this energy source. The selected bioenergy pathway of biogas from anaerobic digestion was found to eliminate some of these barriers. Assessing the potential of biogas using multi appraisal techniques highlighted that this pathway could, in some cases, offer positive environmental, energy and financial benefits.

The detrimental effects of climate change and the threat of diminishing fossil fuel reserves is forcing society to search for renewable sources of energy. Energy can be derived from the biomass of plant material by co-fire combustion with coal or on its own for the production of electricity. Energy can also be created by converting the plant biomass into ethanol, a gasoline substitute. When converted into bioenergy, plant biomass from Short Rotation Woody Crop (SRWC) systems has the potential to offset the use of fossil fuels if the yields can be maintained at profitable levels. The effect of first year application of nitrogen (N) fertilizer on willow biomass production in a SRWC system is not well understood. Using field and growth chamber studies, the objectives of this study were to 1) determine biomass production in the growing seasons following a single application of N fertilizer in the year of planting, 2) determine the N recovery for five willow clones using a 15N tracer, and 3) evaluate the effects of various types and rates of fertilizers on biomass production. Objectives 1 and 2 were addressed in a field fertilization study conducted on agricultural lands in the Moist Mixed Grassland ecozone and at tree nursery in the Boreal Transition ecozone. Willow cuttings were planted and fertilized with 100 kg N ha-1 of granular ammonium nitrate. Twelve trees were fertilized with 5 kg N ha-1 of double 15N-labeled ammonium nitrate and 95 kg N ha-1 of granular ammonium nitrate. In the first growing season trees were browsed to a uniform height making biomass measurements unrepresentative of production potential. Annual shoot biomass production in the second year, however, was 0.39 to 2.0 Mg ha-1 and was not found to be significantly different between fertilizer treatments. Nitrogen recovery by entire trees ranged from 2.87 to 10.6 % in the first growing season and 0.39 to 2.95 % in the second growing season. Objective three was addressed in a growth chamber study. Willow cuttings were planted in pots and fertilized with 0, 50, 100 and 200 kg N ha-1 of granular ammonium nitrate and 100 kg N ha-1 of composted cattle manure. After a 90 day growth period shoot biomass production was significantly greater on the Prince Albert soil (1.28 to 5.34 g tree-1) than on the Saskatoon soil (1.18 to 3.59 g tree-1). No consistent trend between fertilizer treatments was observed. Further exploration into fertilization of willow SRWC systems should consider the application of multiple nutrient fertilizer blends, various rates and year of application to gain a better understanding of nutrient requirements of willow for the entire growth period.

The detrimental effects of climate change and the threat of diminishing fossil fuel reserves is forcing society to search for renewable sources of energy. Energy can be derived from the biomass of plant material by co-fire combustion with coal or on its own for the production of electricity. Energy can also be created by converting the plant biomass into ethanol, a gasoline substitute. When converted into bioenergy, plant biomass from Short Rotation Woody Crop (SRWC) systems has the potential to offset the use of fossil fuels if the yields can be maintained at profitable levels. The effect of first year application of nitrogen (N) fertilizer on willow biomass production in a SRWC system is not well understood. Using field and growth chamber studies, the objectives of this study were to 1) determine biomass production in the growing seasons following a single application of N fertilizer in the year of planting, 2) determine the N recovery for five willow clones using a 15N tracer, and 3) evaluate the effects of various types and rates of fertilizers on biomass production. Objectives 1 and 2 were addressed in a field fertilization study conducted on agricultural lands in the Moist Mixed Grassland ecozone and at tree nursery in the Boreal Transition ecozone. Willow cuttings were planted and fertilized with 100 kg N ha-1 of granular ammonium nitrate. Twelve trees were fertilized with 5 kg N ha-1 of double 15N-labeled ammonium nitrate and 95 kg N ha-1 of granular ammonium nitrate. In the first growing season trees were browsed to a uniform height making biomass measurements unrepresentative of production potential. Annual shoot biomass production in the second year, however, was 0.39 to 2.0 Mg ha-1 and was not found to be significantly different between fertilizer treatments. Nitrogen recovery by entire trees ranged from 2.87 to 10.6 % in the first growing season and 0.39 to 2.95 % in the second growing season. Objective three was addressed in a growth chamber study. Willow cuttings were planted in pots and fertilized with 0, 50, 100 and 200 kg N ha-1 of granular ammonium nitrate and 100 kg N ha-1 of composted cattle manure. After a 90 day growth period shoot biomass production was significantly greater on the Prince Albert soil (1.28 to 5.34 g tree-1) than on the Saskatoon soil (1.18 to 3.59 g tree-1). No consistent trend between fertilizer treatments was observed. Further exploration into fertilization of willow SRWC systems should consider the application of multiple nutrient fertilizer blends, various rates and year of application to gain a better understanding of nutrient requirements of willow for the entire growth period.