Made available in DSpace on 2016-04-28T14:56:17Z (GMT). No. of bitstreams: 1 2009 - Priscila Nogueira Matos.pdf: 1723305 bytes, checksum: 89e42c980c370e9eec2db3e9b08306ae (MD5) Previous issue date: 2009-03-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The Mining is considered the activity can cause a great impact in the environment, involving the vegetation and subsoil layers remove. After the finish of mineral sources, mandatorily these areas require recovery measures. This study aimed to evaluate the initial establishment of three genotypes of palm oil: C2501, C2301 and C2528, indicated by Embrapa Amaz?nia ocidental, in area of mining in the northwest Par?. Was also evaluated the soil fauna, the occurrence of nitrogen fixing bacteria and arbuscular mycorrhizal fungi associated with culture. The establishment of culture was evaluated for survival, height, number of leaves and nutritional status of plants and soil fertility. The impact on soil fauna was evaluated with samples in the experimental area and in areas of reforestation and forest adjacent to it. To determine the presence of mycorrhizal fungi and diazotrophic bacteria samples were taken from roots and soil in the palm oil. The amount of the plant N derived from BNF was determined with the natural abundance of 15N technique. The mortality of the plants was low, but growth was not strong, this may be related to low P in soil and periods of drought. In this initial stage of establishing the symbiosis with diazotrophic bacteria was inefficient where only the genotypes C2501 and C2528 were 4,5 and 4,8% respectively of N derived from BNF, with great variability in the population of bacteria. The mycorrhizal fungi no showed differences in sampled areas and this result may be related to water deficit and sampling period in the dry season. The composition of soil fauna not differ in the areas of palm oil plantation with and without green manure, and conventional reforestation, however not present the same diversity of the forest. / A minera??o ? considerada uma atividade econ?mica que causa um grande impacto ao ambiente, envolvendo a retirada da vegeta??o e camadas do subsolo. Ap?s a exaust?o dos recursos minerais, estas ?reas necessitam obrigatoriamente de medidas de recupera??o. O objetivo deste trabalho foi avaliar o estabelecimento inicial de tr?s gen?tipos de dend?: C2501, C2301 e C2528, indicados pela Embrapa Amaz?nia Ocidental, em ?reas de est?ril da Minera??o de bauxita no noroeste do Par?. Foram avaliados tamb?m a fauna do solo, a ocorr?ncia de bact?rias fixadoras de nitrog?nio e fungos micorr?zicos arbusculares associados ? cultura. O estabelecimento da cultura foi avaliado pela sobreviv?ncia, altura, n?mero de folhas e estado nutricional das plantas, e a fertilidade do solo. O impacto na fauna do solo foi avaliado na ?rea experimental e em ?reas de floresta prim?ria e reflorestamento adjacentes a este. A presen?a de bact?rias diazotr?ficas e fungos micorr?zicos foram determinadas em amostras de ra?zes e solo na ?rea do dend?. A quantidade de N na planta derivado da FBN foi determinada pela t?cnica de abund?ncia natural de 15N. A mortalidade das plantas foi considerada baixa apesar de seu crescimento n?o ter sido vigoroso podendo este estar relacionado ao baixo teor de P no solo e aos per?odos de stress h?drico por falta de ?gua. Neste est?gio inicial de implanta??o a simbiose com bact?rias diazotr?ficas foi pouco eficiente onde apenas os gen?tipos C2501 e C2528 tiveram 4,5 e 4,8% respectivamente de N derivado da FBN, com grande variabilidade na popula??o de bact?rias. Os fungos micorr?zicos n?o apresentaram diferen?as nas ?reas analisadas, tal resultado pode estar relacionado com a defici?ncia h?drica e o per?odo de coleta na ?poca seca. A composi??o da fauna do solo nas ?reas de plantio de dend? com e sem aduba??o n?o diferiram entre si e em rela??o ao reflorestamento convencional, n?o apresentando, entretanto a mesma diversidade da floresta prim?ria.

Made available in DSpace on 2017-05-12T14:46:52Z (GMT). No. of bitstreams: 1 Larissa.pdf: 1850942 bytes, checksum: 055f99877063a1e529d77540c0b94279 (MD5) Previous issue date: 2013-02-01 / Livestock, especially cattle, has been considered one of the main sectors that is responsible for global warming due to rumen methane emission and, to a lesser extent, methane emission by residues. Another concern is the correct disposal of agroindustrial residues. The wet brewery grain is considered as polluting as animal wastes. Thus, such wastes must have correct destination, so their use to feed animal is an option. The wet brewery grain has been recorded as an important substitute for fodder and/or grain in ruminants diet. Thus, this study aimed at evaluating the potential for methane production in cattle fed diets containing different levels of wet brewery grain inclusion, to replace bulky diet, with 0, 20, 25 and 30% rates in dry matter percentage. Four castrated steers, with rumen cannula were studied and distributed in a Latin square design (4x4) in four experimental periods of 21 days each (14 days of adjustment and 7 days for data collection). During the last week of each period, the animals manure and ruminal fluid were collected, whose anaerobic digestion essays were analyzed, during the period of 120 days. So, the following parameters were evaluated: removal of total and volatile solids, removal of soluble chemical oxygen demand, cumulative and daily production of methane, volatile fatty acids production (lactic, acetic, propionic and butyric), acidity/alkalinity ratio and pH of reactors. In order to record ruminal fluid, 96-hour tests were performed in the laboratory to observe the influence of wet brewery grain inclusion on methane and volatile fatty acids production inside the rumen. The statistical evaluation of the process was obtained with curves of cumulative production of methane that were adjusted according to Gompertz modified model. Tukey test was used to compare averages with 5% significance. According to these data, it is concluded that wet brewery grain inclusion influenced on methane production for these animals. There was effect of treatment and period for cumulative production of methane (L). The treatment with the largest inclusion of wet brewery residue showed the highest potential of methane production in wastes. The wet brewery residue inclusion did not affect the production of volatile fatty acids inside rumen. The cumulative methane production (mL) of ruminal fluid was influenced by the inclusion of wet brewery residue on animals diet. Nevertheless, the lowest production occurred with an increasing supply of wet brewery residue. The Gompertz modified model provided a good adjustment to the methane production data. Consequently, wet brewery residue can be considered an alternative diet to replace corn silage up to 30% (DM), since it reduces methane production inside the rumen (environmental benefit) and increases methane production from residues (energy and economic benefit). / A pecuária, sobretudo a bovina, tem sido considerada um dos principais setores responsáveis pelo aquecimento global, devido à emissão de metano ruminal e, em menor proporção, à emissão de metano pelos dejetos. Outra preocupação é a correta destinação dos resíduos agroindustriais. O resíduo úmido de cervejaria é considerado tão poluidor quanto os dejetos animais. Desta forma, é importante que este subproduto tenha destino correto e uma opção é o uso na alimentação animal. O resíduo úmido de cervejaria tem se mostrado um importante substituto para forragens e/ou grãos na dieta de ruminantes. Portanto, o objetivo deste trabalho foi avaliar o potencial de produção de metano de bovinos alimentados com dietas que continham diferentes níveis de inclusão de resíduo úmido de cervejaria (RUC), em substituição ao volumoso da dieta, cujas doses foram: 0, 20, 25 e 30% em porcentagem de massa seca. Foram utilizados quatro bovinos machos, castrados, portadores de cânula ruminal, distribuídos em delineamento quadrado latino (4x4), em quatro períodos experimentais de 21 dias cada (14 dias de adaptação e 7 dias de coleta de dados). Na última semana de cada período, coletaram-se dejetos e líquido ruminal dos animais. Com os dejetos coletados, realizaram-se ensaios de biodigestão anaeróbia, no período de 120 dias, nos quais foram avaliados a remoção de sólidos totais e voláteis, a remoção da demanda química de oxigênio solúvel, a produção diária e acumulada de gás metano, a produção de ácidos graxos voláteis (lático, acético, propiônico e butírico), a relação acidez/alcalinidade e o pH dos reatores. Em relação ao líquido ruminal, foram realizados testes de 96 horas, em laboratório, para verificar a influência da inclusão de RUC na produção de gás metano e ácidos graxos voláteis no rúmen. Para a avaliação estatística do processo, utilizaram-se curvas de produção acumulada de metano, ajustadas segundo modelo de Gompertz modificado. O teste de Tukey foi adotado para comparação das médias, com nível de significância de 5%. Com os dados obtidos, conclui-se que a inclusão de resíduo úmido de cervejaria teve influência na produção de metano nesses animais; houve efeito de tratamento e período para a produção acumulada de metano (L). O tratamento com maior inclusão de resíduo úmido de cervejaria apresentou maior potencial de produção de metano nos dejetos; a inclusão de RUC não alterou o perfil de produção de ácidos graxos voláteis no rúmen; a produção acumulada de metano (mL) do líquido ruminal foi influenciada pela inclusão de resíduo úmido de cervejaria à dieta. Todavia, a menor produção ocorreu com o aumento do fornecimento de resíduo úmido de cervejaria. O modelo de Gompertz modificado apresentou bom ajuste aos dados de produção de gás metano. Logo, o resíduo úmido de cervejaria pode ser considerado alimento alternativo para substituir a silagem de milho, em até 30% (MS), uma vez que diminui a produção de metano no rúmen (benefício ambiental) e aumenta a produção de metano nos dejetos (benefício energético e econômico).

O nitrogênio é o nutriente absorvido em maior quantidade pelo milho e o que mais influencia na produtividade de grãos, tendo sua dinâmica no sistema solo-planta condicionada pelo manejo. O trabalho foi desenvolvido na fazenda experimental da Faculdade de Engenharia de Ilha Solteira, UNESP, Selvíria-MS, em um Latossolo Vermelho distrófico, fase cerrado. Os objetivos do trabalho foram de avaliar a melhor dose e época de aplicação do N, na forma de uréia, no milho cultivado sob semeadura direta (SD) em sucessão à crotalária (CR) (Crotalaria juncea), milheto (MI) (Pennisetum americanum) ou solo em pousio na entressafra; quantificar o aproveitamento pelo milho do N da uréia e do N mineralizado dos resíduos vegetais da parte aérea da CR e do MI; avaliar o efeito dos adubos verdes no aproveitamento do N-uréia e vice-versa, e de averiguar o aproveitamento do N remanescente da uréia e dos adubos verdes pelo milho cultivado em SD no ano agrícola subseqüente. Foram conduzidos dois ensaios em áreas distintas e anexas, nos anos agrícolas de 2001/02 e de 2002/03, com a avaliação, nas respectivas áreas e ano agrícola subseqüente, 2002/03 e 2003/04, do aproveitamento pelo milho do N residual dos adubos verdes e do N do fertilizante e seu efeito sobre a produtividade do milho. O delineamento experimental utilizado foi o de blocos casualizados com 24 tratamentos e quatro repetições, dispostos em esquema fatorial incompleto (3 x 3 x 2) + 6 tratamentos adicionais (três tratamentos controles sem a aplicação de N e três tratamentos que receberam somente 30 kg ha-1 de N na semeadura, sobre CR, MI e solo em pousio. Os demais tratamentos constituíram-se pela combinação de três doses de N: 80, 130 e 180 kg ha-1, aplicando-se 30 kg ha-1 na semeadura e o restante em cobertura; três sistemas de cobertura do solo: CR e MI cultivados no inverno/primavera e o solo em pousio na entressafra, e duas épocas de aplicação do N: estádio quatro folhas ou estádio oito folhas. O fertilizante 15N-uréia foi aplicado nos tratamentos com 30 kg ha-1 de N na semeadura ou 50, 100 e 150 kg ha-1 de N em cobertura nos estádios quatro folhas ou oito folhas. A CR ou MI marcados com 15N foram utilizados somente nos tratamentos receberam o N no estádio quatro folhas, testemunha ou apenas 30 ha-1 de N na semeadura. A produtividade de grãos foi superior no milho em sucessão à CR, nos dois anos agrícolas, em relação ao cultivo em sucessão ao MI e ao solo pousio, que diferiram entre si com menor produtividade na sucessão MI-milho no primeiro ano agrícola e quando o N foi aplicado no estádio oito folhas no segundo. As épocas de aplicação do N não influenciaram no seu aproveitamento pelo milho, mas, a aplicação no estádio quatro folhas demonstrou ser mais viável economicamente quando o milho foi cultivado em sucessão ao MI e ao solo em pousio, e indiferente para o cultivo em sucessão à CR. O incremento na dose de fertilizante nitrogenado proporcionou aumento na quantidade de N na planta proveniente do fertilizante e diminuiu o seu aproveitamento, que foi em média de 53%, 49% e 44% para o milho cultivado em sucessão à CR, pousio e MI, respectivamente. O incremento na dose de fertilizante nitrogenado proporcionou aumento linear no aproveitamento pelo milho do N da CR, e quadrático no segundo ano agrícola para o N do MI, que foi em média de 15,60% 7,60%, respectivamente. A CR promoveu maior aproveitamento pelo milho do N da uréia comparada ao MI, que acumulou proporcionalmente maior quantidade de N proveniente do solo. O aproveitamento do N remanescente da parte aérea do MI e da CR pelo milho cultivado no ano agrícola subseqüente, foi inferior a 3,5% e 3%, respectivamente, da quantidade inicial, e o do N remanescente do fertilizante uréia foi inferior a 3% do aplicado inicialmente. / Nitrogen is the most absorbed nutrient by corn crop and most affect the grains yield, and its dynamic in soil-plant system is conditioned by management. The research was carried in the Experimental Farm of Faculty of Engineering, Sao Paulo State University (UNESP), Ilha Solteira, located in Selvíria-MS, in a dystrophic Red Latosol, cerrado phase, during 2001/02 and 2002/03 growing season. The objectives were to evaluate the best rate and time of N application, as urea, and N utilization by corn crop grown under no-tillage system in succession to sunnhemp (Crotalaria juncea L) (SU), millet (Pennisetum americanum) (MI) and fallow; to quantify the utilization of N from urea and mineralized SU and MI residues by corn crop; to evaluate the effect f green manure on urea N utilization by corn crop and vice-versa; and to investigate the utilization by corn crop of N remnant from previous year applied urea and green manure by corn crop grown subsequent year under no-tillage system. Two experiments were carried out in distinct nearby areas in 2001/02 e 2002/03, with the evaluation, in the respective areas and subsequent years, 2002/03 and 2003/04, of utilization by corn by corn of green manure and fertilizer remnant N and their effects on corn yield. The experimental design was randomized complete blocks, with 24 treatments and four replications in an incomplete factorial, (3 x 3 x 2) + 6 additional treatments (three without N application and three that received 30 kg N ha-1 at seeding); three N rates: 80, 130 and 180 kg N ha-1; tree preceding cover crops SU, MI grown during winter/spring season and fallow; two N application time: four leaves or eight leaves stage. The fertilizer 15N-urea was applied in the treatments 30 kg ha-1 of N at seeding or 50, 100 and 150 kg ha-1 topdressed at four leaves or eight leaves stages. SU or MI labeled with 15N were used only in the treatments that received N in the four leaves stage, control or those which received 30 ha-1 of N at seeding. The grains yield was higher in the corn in succession to SU, in both growing seasons, in relation to the cultivation in succession to MI and the fallow soil, that differed between them, with smaller productivity in the succession MI-corn in the first year and when N was applied at the eight leaves stage in the second. The N application times did not affect its utilization by the corn, but the application in four leaves stage demonstrated to be more economically viable when the corn was grown in succession to MI and the soil in fallow, and indifferent for the cultivation in succession to SU. The amount of N derived from fertilizer (Npdff) increased with increasing N rate and reduced the N utilization efficiency (NUE), in average 53%, 49% and 44% for the corn grown in succession to SU, fallow and MI, respectively. The increasing nitrogen fertilizer rate increased linearly the utilization by corn of N from SU, and adjusted to quadratic model in the second year for N from MI, in average 15.60% 7.60%, respectively. SU promoted larger utilization of urea N compared to MI, which accumulated proportionally larger amount of N derived from the soil than SU. The utilization of N remnant from above ground part of MI and of SU by the corn grown in the subsequent year was less than 3.5% and 3%, respectively, of the initial amount, and the remaining N of the urea fertilizer was less than 3% of initially applied amount.

[Truncated abstract] In Australia, there is pressure to reduce the amount of methane produced by ruminant livestock because they are the single largest source of methane emitted from anthropogenic sources, accounting for 70.7% of agricultural methane emissions. In addition, methane production represents a loss of gross energy intake to the animal. The organisms that are responsible for methane production in the animal gut are a distinct group of Archaea called methanogens. Methanogens occupy three different niches within the rumen. Some live freely in the rumen digesta (planktonic), others are attached to the outer surface of the rumen ciliates (ectosymbiotic), and some reside within the ciliates (endosymbiotic). The types and number of methanogens, as well as rumen ciliates and their symbiotic interactions, influence the amount of methane produced from the rumen. These factors in turn are affected by many factors, including diet and ruminal retention time. In this thesis, I tested the general hypothesis that increasing the amount of grain in the diet and reducing the retention time would affect the abundance and diversity of methanogens in their different niches, including their association with ruminal ciliates. Twenty-four fistulated sheep were used in a complete factorial design with the sheep randomly divided into four groups. ... The change in DGGE banding patterns and Shannon indices when sheep were fed grain indicated that the types of methanogens changed when sheep were fed low and high grain diets, but their diversity did not. In contrast, the diversity of rumen ciliates decreased when sheep were fed a high grain diet. A total of 18 bands from the DGGE analysis of the ciliates were sequenced. All except one, which was 98% similar to Cycloposthium sp. not found previously in the rumen, matched the sequences for previously identified rumen ciliates. Some of the rumen ciliates identified were not present in sheep fed the high grain diet. On a high grain diet, methanogens associate endosymbiotically with rumen ciliates to get better access to hydrogen. It appears that the association between methanogens and rumen ciliates is dictated by the availability of hydrogen in the rumen and not the generic composition of the ciliate population. Furthermore, endosymbiotic methanogens appear to produce less methane than methanogens in other niches. The pot scrubbers did not change ruminal retention time but they did reduce the acetate/propionate measurements observed in sheep on the high grain treatment. The reason why pot scrubbers had this effect remains unknown, but it is interesting to consider that some physical interaction has occurred between the pot scrubbers, the grain and the sheep that has improved the fermentation parameters in sheep fed a high grain diet. The results from this study have advanced our understanding of the interaction between methanogens and ruminal ciliates, and methanogenesis in the rumen in response to dietary changes and mechanical challenges. Extending this work to look more specifically at the species of methanogens that are most closely linked to high methane production and how they interact with the ruminal ciliates will be critical for manipulating enteric greenhouse gas emissions.

Examines the character construction of the Hesiodic ‘farmer’ in the scholarship of Works and Days. Questions Hesiod’s intimacy of agricultural knowledge: was he a practical farmer or a non-farming poet? Using my farming experience I question the adequacy of the information in Works and Days for use as a farming manual. Lines 635-640 - Hesiod’s description of the climatic conditions of Ascra in respect to farming are set against soil properties (soil biochemistry as an evaluating tool) and agricultural responses (farming methods of other cultures) shows Hesiod to have little grasp of the farming methods each situation requires. Text comparatives: Fan Shêng-Chih Shu an ancient Chinese agricultural text detailed with attention to soil fertility. Supporting ancient texts: Cato on Agriculture, Columella on Agriculture, Theophrastus on Plants, Xenophon Oeconomics and Homer’s Odyssey for references to dung and soil fertility. The vague farming information suggests a non-personalized experience - the Hesiodic ‘farmer’ is probably not a practical farmer at all.

Diss. Umeå : Sveriges lantbruksuniv.

Examines the character construction of the Hesiodic ‘farmer’ in the scholarship of Works and Days. Questions Hesiod’s intimacy of agricultural knowledge: was he a practical farmer or a non-farming poet? Using my farming experience I question the adequacy of the information in Works and Days for use as a farming manual. Lines 635-640 - Hesiod’s description of the climatic conditions of Ascra in respect to farming are set against soil properties (soil biochemistry as an evaluating tool) and agricultural responses (farming methods of other cultures) shows Hesiod to have little grasp of the farming methods each situation requires. Text comparatives: Fan Shêng-Chih Shu an ancient Chinese agricultural text detailed with attention to soil fertility. Supporting ancient texts: Cato on Agriculture, Columella on Agriculture, Theophrastus on Plants, Xenophon Oeconomics and Homer’s Odyssey for references to dung and soil fertility. The vague farming information suggests a non-personalized experience - the Hesiodic ‘farmer’ is probably not a practical farmer at all.

The black rhinoceros remains one of the world's extremely endangered species despite a variety of policies to protect it. The black rhinoceros population at the Great Fish River Reserve (GFRR) in the Eastern Cape in South Africa has increased steadily since their re-introduction in 1986. This megaherbivore is a browser, with a diet obtained largely from the short and medium succulent thicket of the GFRR. Knowledge of the preferential diet of the black rhinoceros on the reserve is an important factor for the effective management of the land and the herbivores that compete for its resources. The dietary preferences of the black rhinoceros at the reserve have been established using backtracking methods. In this study the rbcL gene was used to establish an rbcL gene database of the plants from the GFRR and determine the botanical composition of the black rhinoceros dung from the GFRR. Due to the limited number of rbcL gene plant sequences from the GFRR deposited in the GenBank database, 18 plant species from the GFRR were sequenced. Sequence analyses between the partial rbcL gene sequences generated were able to distinguish between plants down to species level. Plant species from the family Euphorbiaceae and Fabaceae showed sequence variation at intra-specific level compared to those of Tiliaceae which were more conserved. The generated rbcL gene sequences from seasonal dung samples were compared to the rbcL gene sequenced from 18 plant species obtained from the GFRR and those from the GenBank database. A wide range of plant species were identified from the dung samples. There were no major differences in botanical composition between the dung samples, except that Grewia spp. were found to dominate in almost all seasons. The results obtained on the free radical scavenging activity of the extracts against 2,2-Diphenyl-l-picrylhydrazyl (DPPH) increased in the order of methanol > ethyl acetate > chloroform. The DPPH free radical scavenging activity of the methanol plant extracts increased in the order Brachylaena elliptica > Plumbago auriculata > Grewia robusta > Azima tetracantha. Methanol extracts on the TLC plate sprayed with Fe³⁺-2,4,6-Tri-2-pyridyl-s-triazine (TPTZ) showed that the compounds present in the extracts react differently to ferric ion, with most compounds unable to reduce ferric ion. Furthermore the methanol extracts were able to exhibit reduction potentials vs. Ag/AgCl at low concentrations. The compounds in the extracts were shown to be phenolic acids and flavonoid glycosides.

Anaerobic digestion (AD) is becoming a widely adopted technology for conversion of organic waste and nutrient-rich fertiliser production due to its cost-effectiveness and sustainability. In this study, a batch experiment was conducted using five different types of food waste and cow dung (CD). No significant difference was observed among the four substrates that produced the highest methane (P<0.05). Based on the batch experiment results, two substrates were selected for semi-continuous digestion and the highest methane yield (67%) was obtained from co-digestion (CO). PCR-DGGE results revealed higher bacterial and archaeal diversity indices in CO as compared to mono-digestion of CD and mixed food waste. The high-throughput sequence analyses revealed that the Operational Taxonomic Units (OTUs) belonging to the phyla Bacteroidetes, followed by Firmicutes, Actinobacteria and Proteobacteria, were dominant in all treatments. The enhanced methane production in CO could be attributed to the neutral pH and partial shift of archaea from Methanosaeta to Methanosarcina. The digestate and fresh CD were screened for plant growth promoting bacteria (PGPB), nutrient and heavy metal content. The dung contained higher concentrations of heavy metals (P<0.05) and potential pathogens in comparison to the digestate. The use of digestate may, therefore, enhance soil fertility with minimal negative environmental effects. / School of Agriculture and Life Sciences / M. Sc. (Life Sciences)

La variété des pratiques de compostage et les différences de nature des substrats modifient la vitesse de dégradation de la matière organique (MO), la qualité finale du compost produit et la part d'émissions sous forme de polluants gazeux. L'optimisation du procédé nécessite la prédiction de ces transformations ou la réalisation d'essais empiriques. Cette thèse analyse les interactions entre les processus biologiques, biochimiques, physico-chimiques et thermodynamiques majeurs à l'origine de la stabilisation de la MO et des émissions gazeuses de CO2, H2O, NH3, N2O. Elle se focalise sur le compostage par aération passive en andain d'effluents d'élevage. La méthode s'appuie sur la modélisation dynamique et des expérimentations. L'impact des interactions entre la biodégradabilité du carbone, la disponibilité de l'azote, l'humidité et la porosité, sur la cinétique et la stœchiométrie des émissions gazeuses est analysé à partir d’observations en conditions contrôlées et sur une plateforme de compostage. Les écarts de répétabilité faibles en conditions contrôlées deviennent élevés en conditions de reproductibilité sur le terrain. Un modèle dynamique de compostage a été développé simulant la stabilisation de la MO et les émissions de CO2, H2O, NH3, N2O. Il est composé de quatre modules simulant les cinétiques d'oxydation de la MO par une population microbienne, les échanges thermiques et l'aération passive, le transfert d'oxygène, les transformations de l'azote. Lors de la phase thermophile, le facteur limitant le plus rapidement l'organisation de la MO est la disponibilité de l'azote. L'abaissement de la porosité entraîne une diminution des pertes gazeuses par l'augmentation de l'organisation de la MO. Le fractionnement initial de la MO ainsi que la teneur initiale en biomasse microbienne sont les facteurs clés pour prédire les cinétiques d'organisation de la MO. La calibration des paramètres d’initialisation du modèle reste à améliorer / The variety of the practices and the differences in nature of the substrates modify the kinetics of degradation of organic matter (OM), the final quality of the produced compost and the fraction emitted as gaseous pollutants. To optimize the composting process, it is required to predict these transformations or to do some empirical test. This thesis analyzes the interactions between the main biological, biochemical, physicochemical and thermodynamic processes which explain the OM stabilization and the gaseous emissions of CO2, H2O, NH3, N2O. Focus is done on windrow composting with passive aeration. The method is based on dynamic semi-empirical modeling of the process and experimentations. The impact of the interactions between bioavailability of carbon and nitrogen, moisture and porosity, on the kinetics and the stoechiometry of the gaseous emissions is analyzed with data gathered in controlled conditions and on a commercial composting plant. The repeatability differences are small in controlled conditions but higher in field conditions. A dynamic model of composting was developed simulating the stabilization of OM as well as the emissions of CO2, H2O, NH3, N2O. This model is composed of four coupled modules which simulate the kinetics of oxidation of OM by a heterotrophic microbial population, the heat transfers leading to the passive aeration, the transfer of oxygen, the transformations of nitrogen. During the thermopilic phase, the first factor limiting the organization of OM is the availability of nitrogen. The decrease in porosity induces a reduction in the gas losses through the increase in the organization of OM. The initial OM fractionation and the initial microbial biomass are the key factors to predict the kinetics of organization of OM. The calibration of the specific parameters used for model initialization needs a further implementation