Transportation costs represent a significant role in the economics of packaged hay and biomass crops. The material’s low bulk density limits transportation efficiency. Density is currently limited by the ability of the baling twine to withstand the expansion forces generated by the baled material shortly after it is ejected from the bale chamber. It was hypothesized that compromising the structure of the plant, particularly the plant nodes could reduce the amount of energy stored in the material as it is compressed and thereby reduce the material’s elastic response to compression. Literature pertinent to the biomass material’s behavior in compression was reviewed. Bulk samples of switchgrass and miscanthus were subject to uniaxial compression, and the required pressure needed to obtain a target density of 256 kg/m3 was compared on a wet and dry density basis. Both switchgrass and miscanthus showed a statistically significant decrease in the required compression pressure, and the interaction between the moisture level and required pressure was also significant. Existing models for the pressure density relationship of compressed bulk material were evaluated for suitability. Individual nodes and internode sections were subject to radial compression and the apparent modulus of elasticity and maximum contact stress were determined.

Lignocellulosic biomass pretreatment is a fundamental step in the production of renewable fuels and chemicals. It is responsible for the disruption and removal of lignin and hemicellulose from the lignocellulosic matrix, improving the enzymatic hydrolysis of cellulose. Alkaline pretreatment has been shown to be successful on agricultural residues and dedicated energy crops. The objective of this study was to evaluate the pretreatment of switchgrass, wheat straw, corn stover, and miscanthus using calcium hydroxide, potassium hydroxide, and sodium hydroxide at the same hydroxyl concentration, 60% moisture content, and two temperatures for seven days. Enzymatic hydrolysis was also performed and the glucose produced measured. The composition of cellulose, hemicellulose, and lignin before and after pretreatment were quantified according to the standard procedures developed by the NREL for biomass. The hydrolysis was performed at 50°C and 150 rpm. The enzyme loading was 60 FPU/g cellulose. Overall, calcium hydroxide pretreatment resulted in the lowest delignification and structural carbohydrates after pretreatment, as well as lowest glucose yield; In addition to having a higher cost and carbon dioxide emission then sodium and potassium hydroxides. Sodium hydroxide and potassium hydroxide had similar performance in terms of composition changes due to pretreatment and glucose yield after enzymatic hydrolysis.

This diploma thesis focuses on the analysis of scientific literature and the current situation in the field of energy crops and world food prices and trying to express the contemporary situation in this area through discourse. It seeks to analyse the relationship between the production of technical and energy crops in relation to the production of food commodities, world food prices and the anticipated growth of the world's population. Analysis of secondary statistical data of selected productions of food commodities in the last 5 years and their comparison with the prices of selected technical and energy crops are trying to define the direct and indirect links between the development of prices of these commodities.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Cassava plays an important role for food security in the tropics, where it is the third main food source. In Rio Grande do Sul State, Brazil, cassava is a subsistence crop for small farms, who use cassava for human and livestock food. The objective of this dissertation was to adapt and test a process-based model for the cassava crop in subtropical environment of the State of Rio Grande do Sul. We made three modifications in the model compared to the original version in Matthews and Hunt (1994): we considered a third independent clock in the cassava development for the onset of starch accumulation, we replaced the rate of leaf appearance sub-model, by the Wang e Engel model modified for cassava, and we modified the leaf senescence sub-model. Calibration of the model was performed by estimating parameters using the trial and error approach (Matthews and Hunt, 1994) that minimized the root mean square error between observed and estimated values, with total of 16 parameters were calibrated. A total of 25 independent datasets from experiments conducted in four sites of Rio Grande do Sul State (Santa Maria, Glorinha, Vera Cruz and Rio Pardo) were used for testing the model performance and a sensitivity analysis was performed running the GUMCAS model for 17 locations throughout the State of Rio Grande do Sul. In general, the calibration and modifications introduced in the GUMCAS model resulted in good simulations of some key ecophysiological processes such as leaf development and growth as well as of storage roots yield for a cassava genotype adapted to the subtropics. The model was able to capture different environmental conditions accross the Rio Grande do Sul State and with some adaptations for inputting data was able to simulate different management practices such as planting date, plant spacing, plant density, partial above-ground pruning during the growing cycle and two growing cycles as well as the effect of extreme weather events such as hail. / A mandioca tem um papel importante na segurança alimentar nas regiões tropicais, onde é a terceira maior fonte de alimentos. No Estado do Rio Grande do Sul é utilizada principalmente como cultura de subsistência nas pequenas propriedades familiares para a alimentação humana e animal. O objetivo nesta dissertação foi adaptar e testar um modelo baseado em processos para a cultura da mandioca em ambiente subtropical no Estado do Rio Grande do Sul. Foram realizadas três modificações no modelo em relação à versão original de Matthews e Hunt (1994): considerou-se um terceiro "relógio" independente no desenvolvimento de mandioca para o início da tuberização, substituímos o sub-modelo da taxa de aparecimento de folhas pelo modelo de Wang e Engel modificado para a mandioca, e foi modificado o sub-modelo de senescência foliar. A calibração do modelo foi realizada através do método dos mínimos quadrados (Matthews e Hunt, 1994), que minimizou o erro quadrático entre os valores observados e estimados, com um total de 16 parâmetros calibrados. Um total de 25 conjuntos de dados independentes de experimentos conduzidos em quatro locais no Estado do Rio Grande do Sul (Santa Maria, Glorinha, Vera Cruz e Rio Pardo) foram utilizados para testar o desempenho do modelo e uma análise de sensibilidade foi realizada no modelo GUMCAS para 17 locais em todo o Estado do Rio Grande do Sul. Em geral, a calibração e as modificações introduzidas no modelo GUMCAS resultou em boas simulações de processos ecofisiológicos chave, tais como o desenvolvimento e crescimento de folhas, bem como o rendimento de raízes tuberosas para um genótipo de mandioca adaptado à região subtropical. O modelo foi capaz de captar as diferentes condições ambientais encontradas no Rio Grande do Sul e com algumas adaptações na introdução dos dados foi capaz de simular diferentes práticas de manejo, tais como plantio, espaçamento, densidade de plantas, poda verde, dois ciclos de crescimento (mandioca de sobreano), bem como o efeito de eventos climáticos extremos, como o granizo.

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Using crops for fuel generates concerns over competition with food uses. As Rajagopal et al (2009) asserts, “In 2008 the world entered a food crisis amid record-high commodity and energy prices that induced hunger and political unrest in developing countries, by export restrictions in top grain-producing countries”. This took place at the same time when biofuel production, reached its pinnacle in developed countries. This paper examines the effect that biofuel prices and or production has had on food prices in Brazil and U.S. by employing the panel cointegration and Dynamic Ordinary Least Squares (DOLS) method of analysis. In regressing food prices as a function of demand and supply factors, such as oil prices, biofuel prices, interest rates and biofuel production, the study found that the increase in biofuels production over the past eighteen years has had a significant impact on food prices. Over the period January 1995- December 2013, the study estimates that a one hundred percent increase in biofuels production across time and between countries results in the increase of food prices by 21,9%. The study therefore rejects the null hypothesis that states, biofuel production does not have a statistically significant negative impact on food prices in U.S. and Brazil. , and accepts the alternative that biofuel production does have a statistically significant negative impact on food prices in U.S. and Brazil. Other predictors of food prices that the study revealed as significant were oil and interest rates. Policy recommendations for other countries like South Africa are therefore, made based on the results obtained.

Herbaceous perennials represent a considerable portion of potential biomass feedstocks available for the growing bioenergy industry. Their chemical composition and biomass yields, which are important in determining ethanol potential on an area and mass basis, vary with plant variety and type, environment, and management practices. Therefore, a study was conducted to assess the variability of lignin and carbohydrate content, biomass yields, and theoretical ethanol yields on an area basis among different herbaceous perennial species combinations grown in Minot (2008) and Williston (2008, 2009, and 2010), North Dakota (ND). After wet chemistry compositional analysis was done, the carbohydrate contents were used to determine theoretical ethanol potential on a mass basis. Using the dry-matter yield, the theoretical ethanol yield on an area basis was also calculated for these biomass species. Total carbohydrate content for the biomass samples in Williston and Minot varied from 45 to 61% dry basis. Analysis of Variance (ANOVA) at a= 0.05 showed that carbohydrate content varied between years and environments. Also an interaction plot shows that no biomass species had consistently higher or lower carbohydrate content in the different environments. Switchgrass (Panicum vigatum L.) grown as single species or together with other perennial grasses had higher dry-matter yield and theoretical ethanol yield potential in Williston irrigated plots while mixtures containing intermediate or tall wheatgrass species (Thinopyrum spp.) produced better yields in Minot non-irrigated plots. Variability in theoretical ethanol yield on a mass basis (3.7% coefficient of variation (CV) in Williston and 9.7% CV in Minot) was much less than the variability in dry-matter yields (27.5% CV in Williston and 14.8% CV Minot). Therefore, biomass production is much more important than composition in choosing species to grow for ethanol production. Recently, many studies have focused on developing faster methods to determine biomass composition using near infrared (NIR) spectroscopy. Other NIR models have been developed on single biomass feedstocks but a broad-based model for mixed herbaceous perennials is yet to be developed. Therefore, NIR calibration models for lignin, glucan, and xylan were developed with 65 mixed herbaceous perennial species using a DA 7200 NIR spectrometer (950 - 1,650 nm) and GRAMS statistical software. The models for lignin and xylan had R(2) values of 0.844 and 0.872, respectively, upon validation and are classified as good for quality assurance purposes while glucan model had an R(2) of 0.81 which is considered sufficient for screening. The R(2) and the root mean square error of prediction (RMSEP) results showed that it is possible to develop calibration models to predict chemical composition for mixed perennial biomass when compared with results for models developed for single feedstock by Wolfrum and Sluiter (2009) and Liu et al. (2010). Studying the variability in predicting constituents using NIR spectroscopy over time (hours and days), it was observed that the average CV was between 1.4 to 1.6%. The average CV due to repacking (presentation) alone was 1.3%. The CVs for NIR predictions ranged between 1.4 to 5.7% while for wet chemistry ranged between 3.8 to 13.5%; hence, NIR predictions were more precise than wet chemistry analysis.

Für den Anbau von Biomasse-Dauerkulturen wie schnellwachsende Baumarten werden Anbauhinweise und -empfehlungen gegeben, die Aspekte des Boden-, Gewässer- und Naturschutzes berücksichtigen. Standorteignung, Wirkungen auf wildlebende Pflanzen- und Tierarten, entstehende Synergieeffekte, Einflüsse auf den Wasserhaushalt, Stoffeinträge in Gewässer sowie klimatische Wirkungen sind Teilaspekte, unter denen die Chancen und Risiken der energetischen Nutzung nachwachsender Rohstoffe im Rahmen eines mehrjährigen Verbundvorhabens in Sachsen untersucht wurden. Ergänzend wurde auch der Anbau einjähriger Energiepflanzen betrachtet.

Von 2005 bis 2011 wurden auf unterschiedlichen Versuchsstandorten in Deutschland die Trockenmasseerträge von Sorghumhirsesorten und Maissorten verglichen. Es stellte sich heraus, dass der Anbau von Sorghumhirsen auf allen geprüften Standorten mit Erfolg möglich ist und eine Alternative zum Mais im Energiefruchtfolgesystem darstellt. Die Sorghum bicolor-Sorten erreichen ein höheres Ertragspotenzial als die Hybridsorten (Sorghum bicolor x sudanense). Die Hybridsorten zeichnen sich durch eine schnellere Abreife aus und erreichen silierfähige Trockensubstanzgehalte. Verglichen mit Mais erzielen die Sorten der Sorghumart Sorghum bicolor insbesondere auf den D-Süd-Standorten gleiche oder bessere Erträge.

Ausgewertet wurde der Anbau von Sorghumhirsen auf Versuchsfeldern unterschiedlicher bodenklimatischer Bedingungen. Dabei variierten Versuchsparameter wie Bodenbearbeitung, Aussaattermin, Saatstärke, Reihenweite, Saattiefe und Unkrautregulierung. Für Sorghum bicolor wurde eine optimale Saatstärke von 25 und für die Sudangräser von 40 Körnern/m² ermittelt. Die Reihenweiten sind von untergeordneter Bedeutung, sodass die übliche Drillweite im Betrieb nicht verändert werden muss. Die Versuche zeigen, dass Sorghum sowohl als Drill-, Einzelkorndrillsaat als auch im Mulchsaatverfahren ausgebracht werden kann. Heft 24/2012 der Schriftenreihe des Landesamtes für Umwelt, Landwirtschaft und Geologie mit dem Titel „Ergebnisse mehrjähriger Sortenversuche Sorghumhirsen“ bilanziert die Trockenmasseerträge von Sorghumhirsesorten im Vergleich zu Mais.