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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Etude des transferts élémentaires et mécanismes biogéochimiques dans le continuum sol-plante-vin par l'utilisation de traceurs isotopiques et biochimiques / Study of elemental transfers and biogeochemical mechanisms in the soil-plant-wine continuum using isotopic and biochemical tracers

Blotevogel, Simon 29 November 2017 (has links)
Dans l'ouest de l'Europe, une grande importance est accordée à la composante sol dans l'élaboration des vins. La nutrition minérale est la principale voie par laquelle le sol peut avoir une influence sur la vigne et par conséquent sur le vin qui en est issu. Dès lors, ce travail de thèse appréhende la question plus large des transferts élémentaires entre le sol et la plante à travers de l'utilisation d'outils géochimiques en milieu viticole. Une combinaison de techniques impliquant des indicateurs classiques tels que les rapports élémentaires ou des bilans de masses ainsi que des traceurs plus innovants comme les rapports isotopiques du Cu et la résonance paramagnétique électronique (RPE) est utilisée. Dans un premier temps, l'influence du sol sur la composition élémentaire du vin a été étudiée dans plus que 200 vins provenant d'Allemagne, d'Espagne, de France, et d'Italie. A cette échelle, le type de sol (classé comme calcaire ou non-calcaire) et les conditions météorologiques apparaissent comme des critères discriminants. Par la suite, deux parcelles viticoles de Soave (Italie) aux sols contrastés ont été étudiées afin de d´déterminer l'influence du type du sol sur les vignes. Même si les sols présentent des propriétés pédologiques différentes, une pédogénèse complexe a induit des propriétés géochimiques similaires. Dans les vignes, les traceurs élémentaires et biochimiques montrent que la variabilité inter-annuelle et inter-individuelle est plus grande que la différence liée au sol lui-même. Néanmoins, il est possible de déterminer quel est le sol considéré par l'étude des rapports isotopiques du Sr. Parmi tous les nutriments et éléments toxiques généralement étudiés pour leur mobilité dans les sols, le cuivre a été suivi dans la dernière partie de cette thèse, essentiellement du fait de son épandage toujours massif comme fongicide en viticulture. En effet, les pesticides cupriques comme la bouillie bordelaise sont utilisés depuis environ 150 ans en viticulture. Le Cu s'accumule d`es lors dans les sols et les conséquences ´ecotoxicologiques en font un sujet de plus en plus sensible. Parmi les pesticides analysés dans notre étude, les rapports isotopiques du Cu varient autant entre les différents fongicides que dans les sols étudiés dans la littérature, rendant ainsi impossible l'utilisation de ces isotopes comme traceurs d'origine du Cu dans les sols. [...] / In western Europe, soil is of primordial importance for wine making. Soil qualities are often discussed and an influence on wine flavor is frequently inferred. However, evidence for a role of soil chemistry on wine composition and taste is scarce, but mineral nutrition of grapevine plants is one possible way of influence. This thesis approaches the complex question of elemental cycling between soil and plant through the use of geochemical tracers in vineyard environments. A combination of traditional tracers such as elemental ratios and mass balances as well as innovative tools such as Cu isotope analysis and electron paramagnetic resonance (EPR) are used on different observation scales. The influence of soil type on wine elemental composition was investigated using over 200 wine samples from France, Germany, Italy and Spain. Results of chemical analysis were then statistically linked to environmental conditions. At this scale, elemental contents of wine vary depending on soil type (calcareous or not), meteorological conditions, and wine making practice. To determine which soil properties can influence the chemical composition of grapevine plants, two vineyard plots on contrasted soils in Soave (Italy) were examined. Soil forming mechanisms were studied along two catenas and subsequently linked to elemental composition of grapevine plants and biochemical markers of plant health. Even though soil morphology was different, complex soil forming processes led to similar geochemical properties of soils. Differences in plant chemical compositions between soil types are small compared to inter-individual and inter-annual variability. However the use of Sr isotopic ratios allows the determination of the pedological origin of plants. In a next step, the fate of Cu pesticides in vineyard soils was studied. Cu-based pesticides have been used for almost 150 years in European vineyards and Cu accumulates in soils, so that the fate of Cu and its ecotoxicological implications are of growing importance. Therefore, Cu mobility in vineyard soils and transfer to grapevine plants were investigated using stable Cu-isotope ratios and EPR-measurements. Isotope ratios of Cu-based fungicides vary largely between products, covering Cu isotope ratios in soils reported in literature and thus making source tracing impossible. However, Cu isotope ratios are useful for tracing biogeochemical mechanisms of Cu transport in soils. The vertical transport of Cu in different soil types was investigated in the Soave vineyard using a combination of mass balance calculations, kinetic extractions and δ65Cu-isotope ratios. Results suggest that Cu can be transported to depth even in carbonated environments. Besides it is shown that heavy organic-bound Cu is lost from carbonated soil columns likely caused by dissolution of Cu carbonates by organic matter. [...]
22

Mesure de la concentration en métaux traces dans la solution de sol par microlysimétrie

Duquette, Marie-Claude 04 1900 (has links)
La présente étude porte sur l’évaluation d’une méthode d’acquisition de la solution de sol présente à l’interface sol-racine, dans la rhizosphère. Cette interface constitue le lieu privilégié de prise en charge par les plantes des contaminants, tels que les métaux traces. Comme les plantes acquièrent ces éléments à partir de la phase liquide, la solution de sol de la rhizosphère est une composante clé pour déterminer la fraction de métaux traces biodisponibles. La microlysimétrie est la méthode in situ la plus appropriée pour aborder les difficultés liées à l’échelle microscopique de la rhizosphère. Ainsi, dans les études sur la biodisponibilité des métaux traces au niveau de la rhizosphère, les microlysimètres (Rhizon©) gagnent en popularité sans, toutefois, avoir fait l’objet d’études exhaustives. L’objectif de cette étude est donc d’évaluer la capacité de ces microlysimètres à préserver l’intégrité chimique de la solution, tout en optimisant leur utilisation. Pour ce faire, les microlysimètres ont été soumis à une série d’expériences en présence de solutions et de sols, où la quantité de solution prélevée et le comportement des métaux traces (Cd, Cu, Ni, Pb, Zn) ont été étudiés. Les résultats montrent que les microlysimètres fonctionnent de façon optimale lorsque le contenu en eau du sol est au-dessus de la capacité au champ et lorsqu’il y a peu de matière organique et d’argile. Les sols sableux ayant un faible contenu en C organique reproduisent mieux le volume prélevé et la solution sous la capacité au champ peut être récoltée. L’utilisation des microlysimètres dans ces sols est donc optimale. Dans les essais en solution, les microlysimètres ont atteint un équilibre avec la solution après 10 h de prélèvement. En respectant ce délai et les conditions optimales préalablement établies (pH acide et COD élevé), les microlysimètres préservent la composition chimique de la solution. Dans les essais en sol, cet équilibre n’a pas été atteint après dix jours et huit prélèvements. Le contenu en matière organique et l’activité microbienne semblent responsables de la modification des concentrations en métaux au cours de ces prélèvements, notamment, dans l’horizon FH où les microlysimètres performent très mal. En revanche, dans l’horizon B, les concentrations tendent à se stabiliser vers la fin de la série de prélèvements en se rapprochant des valeurs de référence. Bien que des valeurs plus élevées s’observent pour les microlysimètres, leurs concentrations en métaux sont comparables à celles des méthodes de référence (extrait à l’eau, lysimètres de terrain avec et sans tension). En somme, les microlysimètres se comportent généralement mieux dans l’horizon B. Même si leur utilisation est plus optimale dans un sol sableux, cet horizon est privilégié pour de futures études sur le terrain avec les microlysimètres. / This study focuses on evaluating a method of acquiring soil solution in the soil-root interface of the rhizosphere. The liquid phase of the rhizosphere constitutes the main area where plants absorb contaminants like trace metals. Thus the rhizosphere soil solution is key to determine the amount of bioavailable trace metals. Microlysimetry has been described as the most appropriate in situ method to tackle difficulties inherent to the microscopic scale of the rhizosphere. Despite the lack of an exhaustive evaluation of their performance, microlysimeters have gained popularity for in situ studies on the bioavailability of trace metals. The objective of this study was to evaluate the capacity of microlysimeter to preserve the chemical integrity of the soil solution and also to determine their optimum use conditions. To do this, microlysimeter have been submitted to a series of laboratory experiments with solutions and soils. The volume of solution extracted and trace metals (Cd, Cu, Ni, Pb, Zn) behaviour were studied. Results show that microlysimeters work optimally when soil water content is above field capacity and when the amount of clay and organic matter is low. Sandy soils with low organic carbon content have a better reproducibility for extracted volume and soil solution extraction is possible even when soil water content is below field capacity. Using microlysimeters in this soil type is thus optimal. In solution experiments, microlysimeters reached equilibrium with the control solution after ten hours of extraction. In optimal conditions (acidic pH and high DOC) and after this ten hours period, microlysimeters preserve the chemical composition of the solution. In soil experiments, this equilibrium has not been reached after eight samplings throughout ten days. Organic matter content and microbial activity could be responsible for the modification of concentrations of trace metals during sampling. This is especially true for FH horizon where microlysimeters perform poorly. In contrast, the concentrations reach the reference values toward the end of sampling serie in the B horizon and microlysimeters have a better overall performance in this horizon. Although higher values are observed for microlysimeters, trace metals concentrations are comparable to other extraction methods, specifically for the B horizon. Even if their uses are optimized in sandy soil, the B horizon should be privileged for future field studies involving microlysimeters.
23

Monitoring the Influence of Acid Deposition on Soil and Implications to Forest Health in the Daniel Boone National Forest

Sanderson, Tyler M 01 January 2014 (has links)
Combustion of fossil fuels has contributed to many environmental problems including acid deposition. The Clean Air Act (CAA) was created to reduce ecological problems by cutting emissions of sulfur and nitrogen. Reduced emissions and rainfall concentrations of acidic ions have been observed since the enactment of the CAA, but soils continue to receive some acid inputs. Soils sensitive to acid deposition have been found to have low pH, a loss of base cations and a shift in the mineral phase controlling the activity of Al3+ and/or SO42-. If inputs continue, soil may be depleted of base cations and saturated with Al and could cause low forest productivity. Soil solutions from lysimeters were taken in the Daniel Boone National Forest to evaluate potential impacts of acid deposition. In addition, tree-ring growth and chemical analysis created a timeline of forest health and ion accumulation. Physicochemical characteristics of the soils revealed that sites were very low in base saturation and pH and high in exchangeable acidity. Soil solution data indicated that sites periodically received high acid inputs leading to saturation of Al in soils and the formation of Al-hydroxy-sulfate minerals. Given these conditions, long-term changes in soil chemistry from acid deposition are acknowledged.
24

Nitrato na solução do solo e na água de fontes para consumo humano numa microbacia hidrográfica produtora de fumo / Nitrate in the soil solution and in the water of wells used for human consumption in a tobacco producing watershed

Kaiser, Douglas Rodrigo 24 November 2006 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The tobacco production system in Rio Grande do Sul state is mainly developed in small farms, using shallow soils in steep slope. In these areas rivers are born forming small watersheds. The areas are fragilized by use of inappropriate tillage systems causing soil degradation. To compensate this, new areas are included in the production system, after deforestation and not following environmental legislations rules. In order to maintain yield of the degraded areas is needed high fertilization rates and agrochemical application, following a technology package recommended by tobacco industry. Adding to this the fact, that tobacco has a low efficiency of nutrient use. The objective of this study, was monitored the nitrate concentration of soil solution in several soil management and use and in two domestic well used for drinking water. The study was carried out at Arroio Lino watershed, located in Nova Boemia district of Agudo county, state of Rio Grande do Sul. The area of the watershed presents high steepness and it prevails Entisols and mollisols.The soil solution was extracted with tension lysimeters equipped with ceramic porous cup installed at rooting depth (0,15 or 0,2 m) and below this depth (0,3 or 0,5 m), after the main rains happened during the tobacco cycle.The precipitation data were obtained from an automated meteorological station installed at central part of watershed. In 2004/2005 agricultural year, the nitrate concentration was measured in lysimeters installed in a soil management experiment, in an Entisol, including tobacco no-tillage (NT), minimum tillage (MT) and conventional tillage (CT). In 2005/2006 agricultural year, the nitrate concentration was measured in five transects distributed in several places of the watershed, including tobacco plantation, forest and grass field. Two domestic wells located at lower position of landscape were monitored to nitrate concentration. One of those was located at a position which had above it 15 m stripe of forest and after had tobacco plantation, and the other had no tobacco plantation at position above it. At the points of each transect was evaluated bulk density, soil porosity, saturated hydraulic conductivity and soil water retention curve. The soil tillage systems experiment showed higher value of nitrate concentration after starter fertilization application and decreased along of plant cycle, with content varying from 8 to 226 mg L-1. The highest concentration was observed at MT and lowest at NT. The average nitrate concentration in the rooting zone (0,2 m) was 75 for PD, 95 for MT and 49 mg L-1 for CT. Below the rooting zone, the average was 58 for NT, 108 for MT and 36 mg L-1 for CT. The soil in the transects presented low bulk density, low water storage, high porosity and high saturated hydraulic conductivity. The nitrate reached depths bellow rooting zone and its concentration was higher at tobacco plantation than at forest and grass field, reaching values as high as 80 mg L-1 in tobacco plantation. The well located below tobacco plantation had higher nitrate concentration, overcoming the critical limit of 10 mg L-1 in some periods. / A fumicultura no Rio Grande do Sul é desenvolvida em propriedades familiares em regiões ecologicamente frágeis, com solos rasos e alta declividade. Nessas regiões nascem rios e ocorre a formação de pequenas bacias hidrográficas. As áreas são fragilizadas por sistemas de manejo do solo impróprios para aquelas condições e, para manter a capacidade produtiva, recebem anualmente altas doses de fertilizantes e agrotóxicos, seguindo-se um pacote tecnológico difundido pelas agroindústrias fumageiras, que desconsidera as condições ambientais e os atributos do solo. O objetivo deste trabalho foi monitorar a concentração de nitrato na solução do solo, sob diferentes condições de uso e manejo, e na água de duas fontes usadas para o abastecimento doméstico, e relacioná-las com a influência antrópica. O estudo foi conduzido na microbacia hidrografia do Arroio Lino, localizada no distrito de Nova Boêmia, Agudo-RS. A área da microbacia apresenta alta declividade e nela predominam Neossolos e Chernossolos. A solução do solo foi extraída com lisímetros de tensão com cápsulas porosas na região da zona radicular do fumo (0,15 a 0,20 m) e abaixo dessa (0,30 a 0,50 m), logo após as principais chuvas ocorridas durante o ciclo do fumo. Os dados de precipitação foram obtidos de uma micro-estação meteorológica automatizada instalada na microbacia. Na safra de 2004/2005, os lisímetros foram instalados num experimento, sob Neossolo Litólico, com sistemas de manejo para a implantação da cultura do fumo, sendo monitorado o sistema plantio direto (PD), cultivo mínimo (CM) e preparo convencional (PC). Na safra de 2005/2006, os lisímetros foram instalados em cinco transeções distribuídos na paisagem, abrangendo lavouras de fumo, mata e campo nativo. As duas fontes monitoradas estavam localizadas na encosta, sendo que uma delas apresentava uma faixa de 15 m de mata na sua volta e, acima dessa, era cultivado fumo. A outra fonte estava protegida pela mata e não apresentava influência antrópica nas suas proximidades. Nos pontos de cada transeção, avaliaram-se a densidade do solo, porosidade do solo, condutividade hidráulica saturada e curva de retenção de água. Nos sistemas de manejo do solo os teores de nitrato variaram de 8 a 226 mg L-1 e foram maiores após a adubação de base e decresceram ao longo do ciclo. Os níveis mais altos foram obtidos no CM e os menores no PD. Os teores médios de nitrato na zona radicular foram de 75 no PD, 95 no CM e 49 mg L-1 no PC. Abaixo da zona radicular os teores médios foram de 58 no PD, 108 no CM e 36 mg L-1 de nitrato no PC. O solo nas transeções apresentou baixa densidade, baixa capacidade de armazenamento de água, alta porosidade e alta condutividade hidráulica saturada. O nitrato atingiu profundidades abaixo da zona de exploração radicular (0,5m). Os teores de nitrato foram superiores nas lavouras em relação ao campo e à mata nativa, atingindo 80 mg L-1 nas áreas com fumo. A fonte (poço) que se encontrava abaixo das lavouras de fumo teve maiores concentrações de nitrato, superando o limite crítico de 10 mg L-1 em alguns períodos.
25

Aspectos nutricionais de um sistema agroflorestal com eucalipto no sul do Rio Grande do Sul, Brasil / Nutritional aspects in an agroforestry system with eucalyptus in south Brazil

Calil, Francine Neves 16 May 2008 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This study was conducted at an experimental area at Aroeira Farm, belonging to Votorantim Celulose e Papel company, under the geographic coordinates 31° 45 50.7 S e 53° 50 34.9 W, located in Candiota county. In the area there is an experimental field, where some production factors involved in an agroflorestry system are being monitored, with four different treatments (T 1 = eucalyptus planted in 3 m x 2 m spacing; T2= native grass; T3 agroforestry system planted in double line and T4 agroforestry system planted in triple line). Because of this, this study was divided in four chapters, that are: 1) Biomass and nutrients in the agroforestry components in the south of Rio Grande do Sul, Brazil, where the above ground biomass from eucalyptus, sorghum and sunflower was quantified, as well as the nutrients in it. As above ground biomass, sorghum showed a total of 9.876 kg ha-1 (17,67% in the leaves, 47,74% in the stem and 34,61% in grains. In sunflower, the total biomass above the gound was 11.968 kg ha-1 (21,62% in blossom, 24,03% in the leaves, 21,32% in grains and 22,03% in the stem). Eucalyptus total above ground biomass totalized 10.974 kg ha-1 (45,28% in wood, 26,31% in branches, 19,96% in leaves and 8,45% in bark). The total amount of nutrients in sorghum followed this magnitude for total: C > N > K > Ca > P > Mg > S > Fe > Al > Na > Mn. In sunflower the total amount followed this magnitude: C > K > N > Ca > Mg > P > S > Na > Fe > Al > Mn. In eucalyptus the magnitude for total was: C > N > Ca > K > Mg > P > S > Na > Mn > Al > Fe; 2) Inputs through precipitation in área in south Rio Grande do Sul, Brazil, where in native grass area are installed 10 plastic rain gauges (23 cm of diameter). The volume quantification as well as the composed sampling collections for pH, electrical conductivity, nitrate, nitrite, ammonium, phosphorus, sulphur, chlorine, calcium, magnesium, potassium and calcium analysis were collected every fifteen days. The total precipitation during the studied period was 1.605,79 mm, being 13, 56% higher than the average for the region (from September, 3006 to August, 2007). The average pH was 6,59, being the lowest value as 5,66 and this is not considered as acid rain. The average electrical conductivity was 52,84. Sodium showed an average concentration of 2,52 mg/L; potassium 1,07 mg/L; calcium 1,15 mg/L; magnesium 0,17 mg/L; nitrate 0,13 mg/L of N; nitrite 0,52 mg/L of N; ammonium 1,14 mg/L of N; phosphorus 0,66 mg/L; sulphur 0, 19 mg/L, and chlorine 1,60 mg/L. The input through rain precipitation followed this magnitude: Na > Cl > N > K > Ca > S > P >Mg; 3) Soil solution chemical characteristics in an agroforestry system in south Rio Grande do Sul, where the objective was to chemically evaluate the soil solution, in two differend depths (30 cm and 80 cm), in four different treatments )T1 = eucalyptus planted in 3 m x 2 m spacing; T2= native grass; T3 agroforestry system planted in double line and T4 agroforestry system planted in triple line). For sampling collections, lisimeters were used (8 in each depth and in each treatment), accionated by vacuum pumps (through timers), every four hours, kept turned on for 10 minutes. The soil solution samples were collected every fifteen days and sent to pH, electrical conductivity, nitrate, nitrite, ammonium, phosphorus, sulphur, chlorine, calcium, magnesium, potassium and calcium analysis. Soil solution behavior, in different depths and different treatments, showed to be highly variable, considering the kind of crop involved; 4) This chapter had as objective to demonstrate a partial summary from the biogeochemical in the agroforestry system studied, showing the macronutrients distribution in above ground biomass and in the soil. For this, as inputs, it was considered the rain and dust and also fertilizations done for sorghum, sunflower and eucalyptus. Through a scheme, al the fraction and parts that would be evaluated in these system during the 7 years of this study. The calculations were based on the water precipitation samples and on vegetal tissues analysis; for soil calculations it was used the soil analysis. In this study it was possible to quantify the macronutrients inputs and its absorption through the crops and also the amounts of these nutrients in soil; next year it is going to be possible to quantify the nutrients inputs through stem flow, internal precipitation and litter. The runoff is also going to be calculated through soil solution samples collected through lisimeters already installed in the field The inputs of nitrogen totalized 179, 76 kg ha-1 through precipitation and fertilization; phosphorus totalized 74, 31 kg ha-1 through precipitation and fertilization, potassium through precipitation and fertilization totalized 79, 37 kg ha-1 ,calcium 14,12 kg ha-1 and magnesium 2,09 kg ha-1. Soil had 432, 49 kg ha-1 of nitrogen, 63,61 kg ha-1 of phosphorus, 1.656 kg ha-1 of potassium, 65.250 kg ha-1 of calcium and 5.439,60 kg ha-1magnesium. / Este estudo foi realizado em área experimental da Fazenda Aroeira, pertencente a empresa Votorantim Celulose e Papel, unidade Rio Grande do Sul, sob coordenadas geográficas 31° 45 50.7 S e 53° 50 34.9 W, localizada no município de Candiota. Na área, existe uma base de pesquisa,onde estão sendo monitorados os fatores de produção envolvidos em um sistema agroflorestal, com quatro diferentes tratamentos (T1 = eucalipo solteiro plantado em espaçamento 3 m x 2 m; T2 = campo nativo (testemunha); T3 = SAF (eucalipto plantado em linha dupla), T4 = SAF (eucalipto plantado em linha tripla)). Para tanto, este estudo foi dividido em quatro capítulos, os quais são: 1) Biomassa e nutrientes nos componentes de um sistema agroflorestal no sul do Rio Grande do Sul, onde foi quantificada a biomassa acima do solo dos componentes eucalipto, sorgo e girassol, bem como os nutrientes nela contidos. Como biomassa acima do solo, o sorgo apresentou um total de 9.876 kg ha-1 (17,67% nas folhas, 47,74% no colmo e 34,61% nos grãos. No girassol, a biomassa total acima do solo totalizou 11.968 kg ha-1 (21,62% no capítulo, 24,03% nas folhas, 21,32% nos grãos e 22,03% no caule). A biomassa acima do solo total no eucalipto, aos 16 meses, totalizou 10.974 kg ha-1 (45,28% na madeira, 26,31% nos galhos, 19,96% nas folhas e 8,45% na casca). O conteúdo de nutrientes na cultura do sorgo apresentou-se na seguinte magnitude para o total: C > N > K > Ca > P > Mg > S > Fe > Al > Na > Mn. Na cultura do girassol, a magnitude de distribuição dos nutrientes na biomassa total, foi: C > K > N > Ca > Mg > P > S > Na > Fe > Al > Mn. No eucalipto, a magnitude da distribuição do total de nutrientes foi: C > N > Ca > K > Mg > P > S > Na > Mn > Al > Fe; 2) Entrada de nutrientes via precipitação pluviométrica em área no sul do Rio Grande do Sul, onde em área de campo nativo estão instalados 10 funis plásticos, de 23 centímetros de diâmetro, coletores de água da chuva. A quantificação do volume de água armazenado, bem como coleta de amostras compostas para determinação de pH, condutividade elétrica, nitrato, nitrito, amônia, fósforo, enxofre, cloro, cálcio, magnésio, potássio e cálcio foram realizadas quinzenalmente. A precipitação total ocorrida no período de setembro de 2006 a agosto de 2007 foi de 1605,79 mm, sendo 13,56% maior que a média para a região. O pH médio da água da chuva foi 6,59, sendo o menor valor o de 5,66 e este não é considerado como de ocorrência de chuva ácida. A condutividade elétrica média foi 52, 84. O sódio apresentou concentração média de 2,52 mg/L; o potássio 1,07 mg/L; o cálcio 1,15 mg/L, o magnésio 0,17 mg/L, o nitrato 0,13 mg/L de N; o nitrito 0,52 mg/L de N; a amônia 1,14 mg/L de N, o fósforo 0,66 mg/L; o enxofre 0,19 mg/L; e o cloro 1,60 mg/L. O aporte de nutrientes ao sistema agroflorestal em estudo, via precipitação pluviométrica, ocorreu na seguinte magnitude: Na > Cl> N > K > Ca > S > P > Mg; 3) Características químicas da solução do solo em um sistema agroflorestal no sul do Rio Grande do Sul, onde se teve por objetivo avaliar quimicamente a solução do solo, em duas diferentes profundidades (30 cm e 80 cm), em quatro diferentes tratamentos. Para a coleta das amostras, foram utilizados lisímetros (8 em cada profundidade e em cada tratamento,), acionados por bombas de vácuo (através de timers), a cada 4 horas, permanecendo ligados durante 10 minutos. As amostras de solução do solo foram coletadas a cada quinze dias e encaminhadas para análise de: pH, condutividade elétrica, sódio, potássio, cálcio, magnésio, fosfato, sulfato, cloreto, nitrito, nitrato e amônia.O comportamento da solução do solo, nas diferentes profundidades e diferentes tratamentos, apresenta-se bastante variável, considerando o tipo de cultura envolvida (eucalipto solteiro, campo nativo ou sistema agroflorestal); 4) Este capítulo teve por objetivos demonstrar um resumo parcial da biogeoquímica do sistema agroflorestal em estudo, mostrando a distribuição dos macronutrientes na biomassa acima do solo e no solo. Para tanto, foram considerados como entradas no sistema, a poeira e precipitação pluviométrica e a adubação realizada nas culturas agrícolas, sorgo e girassol e para o eucalipto. Através de um esquema, demonstrou-se todas as frações e partes que serão avaliados nesse sistema agroflorestal nos 7 anos de duração desse estudo. Os cálculos foram realizados com base nas análises realizadas em laboratório, das amostras de água da chuva e dos tecidos vegetais; para o cálculo dos nutrientes no solo, utilizou-se a análise de solo realizada para o mesmo. No presente estudo, foi possível quantificar as entradas de macronutrientes, a absorção dos mesmos pelas culturas e o conteúdo destes no solo; futuramente; será possível quantificar as entradas provenientes do gotejamento das copas, precipitação interna, escorrimento pelo tronco e serapilheira. Também será possível avaliar a lixiviação, com base nos dados provenientes da solução do solo coletados através de lisímetros já instalados. As entradas de nitrogênio totalizaram 179, 76 kg ha-1 pela precipitação e adubação; o fósforo totalizou 74, 31 kg ha-1 pela precipitação e adubação, o potássio via precipitação e adubação totalizou 79, 37 kg ha-1 ,o cálcio via precipitação e adubação totalizou 14,12 kg ha-1 e o magnésio via precipitação e adubação totalizou 2,09 kg ha-1. O solo apresenta 432, 49 kg ha-1 de nitrogênio, 63,61 kg ha-1 de fósforo, 1.656 kg ha-1 de potássio, 65.250 kg ha-1 de cálcio e 5.439,60 kg ha-1de magnésio.
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Ciclagem biogeoquímica dos nutrientes em uma plantação de Pinus taeda L. no nordeste Argentino / Nutrient biogeochemical cycling in a Pinus taeda L. plantation in northeast of Argentina

Caldato, Silvana Lucia 18 March 2011 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objectives of this study were to characterize water and nutrient fluxes in a Pinus taeda plantation at 12 year-old located in the northeast of Argentina. The atmospheric deposition and rainfall partitioning into throughfall, stemflow and canopy interception loss and the chemical composition of soil solution in the pinus plantation and in a grassland area was evaluated during a year. Three rain collectors were installed in the grassland area to measure and collect the rainfall (bulk precipitation), twelve rain collectors were installed in the interior of the plantation to measure the throughfall and twelve stemflow collectors (in selected trees) were used to determine the stemflow. To study the chemical composition of the soil solution two sets of tension lysimeters were installed: one in a Pinus taeda plantation and another one in the open area. To collect soil solutions at the depths of 30 and 70 cm sixteen lysimeters were placed in each area. The biomass was quantified and the stock of nutrients in the tree component was estimated, as well as the accumulated litter on the floor and the soil at 1 m of depth. The annual rainfall was 2228 mm, the pine canopy intercepted on average 26,5% and the net precipitation was 73,5%, of which, 68,9 % was by throughfall and 4,6% by stemflow. The anions N-NO3-, SO42- and N-NO2- and the cations Na+ and Ca2+ were the main chemical inputs from bulk precipitation. The transfer of fluxes through the canopy and stems of pine caused an enrichment for most elements mainly potassium and magnesium. The solution of the soil under pine plantation showed a high concentration of ions, mainly base cations (exchangeable), in its composition compared with the grassland area, indicating the importance of nutrient cycling in forest ecosystem. The main budget of nutrients in the pine stand is a non-commercial biomass (needles, branches, roots and litter), showing that depending on the adopted management practices, the output of nutrients may be less than the budget that remains in the site after the forest harvesting. / O objetivo deste estudo foi caracterizar fluxos hídricos e nutricionais em uma plantação de Pinus taeda com 12 anos de idade, localizada no Nordeste da Argentina. As deposições atmosféricas e a distribuição da precipitação global em precipitação interna, escorrimento pelo tronco e perdas por interceptação do dossel, bem como a composição química da solução do solo na plantação de pinus e em área de campo, foram avaliadas durante o período de um ano. Três pluviômetros foram instalados na área de campo para medir e coletar a precipitação global. Para medir a precipitação interna, 12 pluviômetros foram instalados no interior da plantação e 12 coletores foram utilizados (em árvores selecionadas) para determinar o escorrimento pelo tronco. Para estudar a composição química da solução do solo, foram instaladas duas bases de lisímetros de tensão: uma na plantação de Pinus taeda e outra em área de campo. Para coletar a solução do solo nas profundidades de 30 e 70 cm, 16 lisímetros foram posicionados em cada área. A biomassa foi quantificada e o estoque de nutrientes foi estimado em diferentes componentes das árvores, assim como a serapilheira acumulada sobre o solo, e o solo a 1 m de profundidade. A precipitação anual foi de 2228 mm, sendo que a interceptação pelo dossel do pinus foi de 26,5%, e a precipitação efetiva foi de 73,5%, da qual 68,9% foram da precipitação interna e 4,6% do escorrimento pelo tronco. Os principais íons que entraram pela precipitação foram os ânions N-NO3-, SO42- e N-NO2- e os cátions Na+ e Ca2+. A passagem da água da chuva pelas copas e troncos ocasionou a adição de vários elementos, principalmente de potássio e de magnésio. A solução do solo sob plantação de pinus apresentou uma elevada concentração de íons, principalmente de cátions básicos (trocáveis) em sua composição quando comparada com a área de campo, indicando a importância da ciclagem de nutrientes no ecossistema florestal. O maior estoque de nutrientes no povoamento se encontra na biomassa não comercial (acículas, galhos, raízes e serapilheira), mostrando que dependendo das práticas adotadas de manejo, a saída de nutrientes pode ser menor do que o estoque que permanece no sítio depois da colheita florestal.
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Prognóstico da toxidez de ferro em arroz irrigado por alagamento através da análise de solo pelo método oxalato de amônio / Prognosis of iron toxicity in rice by flooding through the analysis of soil by ammonium oxalate method.

Wolter, Roberto Carlos Doring 05 March 2010 (has links)
Made available in DSpace on 2014-08-20T13:25:43Z (GMT). No. of bitstreams: 1 Dissertacao_Roberto_ Carlos_Doring_ Wolter.pdf: 973904 bytes, checksum: 67cf8c20b65c6a70b13833df022a0d9c (MD5) Previous issue date: 2010-03-05 / Iron toxicity can cause considerable reductions in the productivity of rice, depending on the severity of symptoms and the affected area in the field. It is necessary to identify the factors that determine the occurrence of this nutritional disorder, so that effective measures may be carried out to correct this problem in the field. The objective of this study is to verify that the interpretation criteria for prognosis of the risk of iron toxicity in flooded rice using the soil analysis are reliable for a particular group of lowland soils. Thus, an experiment was conducted in the greenhouse, and the treatments made up of eleven lowland soils structured with a one-factor randomized block design, with four replications. The indicators were: iron extracted from the soil and the CEC, to estimate the percentage of saturation of CEC by Fe2+, percentage of symptoms of iron toxicity, weight of dry matter, and calcium, magnesium, iron and manganese contents in the soil solution and plant tissue. The results were subjected to analysis of variance (Duncan test) at 5% probability, and simple linear correlation of Pearson analyzes (whereas levels greater than 95%). The indicators which have the best efficiency to predict the risk of toxicity by iron is the iron concentrationt in the soil solution and PSFe2+. The PSFe2+ has a high correlation coefficient with the concentration of iron in the soil solution. No symptoms of toxicity by iron is observed when the mole ratio of iron by divalent cations in soil solution is less than 0.30. The extraction of iron by ammonium oxalate at pH 6.0 is a good indicator for estimating the iron that is accumulated during the flooding. The interpretation for prediction of the risk of occurrence of iron toxicity in rice proposed by SOSBAI (2007) based on PSFe2+ is efficient for predicting the occurrence of the problem for the group of soils in the study. / A toxidez de ferro pode causar reduções consideráveis na produtividade do arroz, dependendo da intensidade dos sintomas e da área afetada na lavoura. É necessário identificar os fatores que determinam a ocorrência dessa desordem nutricional, afim de que possam ser realizadas medidas efetivas para corrigir esse problema na lavoura. O objetivo do presente trabalho é verificar se os critérios de interpretação para prognóstico do risco de ocorrência da toxidez por ferro em arroz irrigado por alagamento a partir da análise de solo são válidos para um determinado grupo de solos de várzea. Para isso, foi conduzido um experimento em casa de vegetação, sendo os tratamentos compostos por onze solos de várzea estruturados num unifatorial com delineamento em blocos casualizados, com quatro repetições. Os indicadores avaliados foram: ferro extraído do solo e a CTC, para a estimação da porcentagem de saturação da CTC por Fe2+, porcentagem de sintomas de toxidez por ferro, peso de massa seca, e as concentrações de cálcio, magnésio, ferro e manganês na solução do solo e na parte aérea das plantas. Os resultados foram submetidos à análise de variância (teste de Ducan) a 5% de probabilidade, e realizadas análises de correlações lineares simples de Pearson (considerando níveis maiores que 95%). Os indicadores que apresentam a melhor eficiência para prever o risco de ocorrência de toxidez por ferro são a concentração de ferro na solução do solo e a PSFe2+. A PSFe2+ apresenta alto coeficiente de correlação com a concentração de ferro na solução do solo. Nenhum sintoma de toxidez por ferro é observado quando a fração molar de ferro pelos cátions divalentes na solução do solo é inferior a 0,30. A extração de ferro por oxalato de amônio a pH 6,0 é um bom indicador para se estimar o ferro que é acumulado durante o alagamento do solo. A interpretação para prognóstico do risco de ocorrência da toxidez por ferro em arroz irrigado proposto por SOSBAI (2007) baseada na PSFe2+ é eficiente para previsão da ocorrência do problema para o grupo de solos do estudo.
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Dinâmica de acidificação e de liberação de metais na solução do solo de perfis de solos construídos na área de mineração de carvão de Candiota, RS / Dynamic of acidification and release of metals in the soil solution of constructed soils in Candiota coal mine area, RS - Brazil

Bitencourt, Dioni Glei Bonini 09 September 2014 (has links)
Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2016-09-23T16:14:28Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE.pdf: 6406097 bytes, checksum: d7e90d4c5b8540ce3480587c0129fc13 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2016-09-23T19:13:22Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE.pdf: 6406097 bytes, checksum: d7e90d4c5b8540ce3480587c0129fc13 (MD5) / Made available in DSpace on 2016-09-23T19:13:22Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) TESE.pdf: 6406097 bytes, checksum: d7e90d4c5b8540ce3480587c0129fc13 (MD5) Previous issue date: 2014-09-09 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / O carvão mineral e rochas associadas podem conter pirita, que ao entrar em contato com ar ou água sofre oxidação, produzindo ácido sulfúrico. Essa acidez acelera dissolução dos minerais do solo e aumenta a concentração de metais pesados na solução do solo, criando a drenagem ácida da mina que contamina as águas superficiais e subsuperficiais. Este estudo teve o objetivo de investigar o efeito da drenagem ácida nas propriedades químicas e na retenção da solução do solo construído numa área de mineração de carvão em Candiota, RS. Foram abertas trincheiras e coletadas amostras deformadas e indeformadas, em quatro profundidades (0-10; 40-50; 100-110; 190-200 cm), bem como instalados lisímetros de sucção e sensores de umidade, em perfis de solos construídos de diferentes idades e morfologia (sem terra vegetal: MII-T1 – 28 anos; com terra vegetal: MIV-T1 – 18 anos, MIV-T2 – 17 anos, MVII-T3 – 10 anos, MIV-T4 – 4 anos). Nas amostras deformadas foram realizadas análises físicas e químicas básicas (granulometria, pH (em água, em CaCl2), índice SMP, cátions trocáveis, acidez potencial e carbono orgânico), metais extraídos pelo método US-EPA3050, o potencial de acidificação (PA) e de neutralização (PN) pelo método do peróxido de hidrogênio, bem como a mineralogia, analisada por difratometria de raios X na forma de pó na amostra total. Para a coleta de solução do solo a campo foram instalados lisímetros de sucção (ecoTech, Bonn, Germany) e o monitoramento da umidade do solo foi feito com sensores de umidade (Watermark). A obtenção da solução do solo em laboratório foi feita pelo método do extrato da pasta saturada. Os metais e os cátions básicos das soluções do solo obtidas pelos dois métodos foram analisadas por ICP-OES e o Si e o S determinados por espectroscopia UVvisível e os resultados comparados por testes não paramétricos e em diagramas de estabilidade mineral. Foram obtidas curvas de retenção de solução do solo por câmara de Richards e pelo WP-4 e calculada a capacidade de água disponível em função do potencial osmótico. Concluiu-se que (a) todas camadas de estéril dos solos construídos possuem potencial de acidificação e que as camadas de terra vegetal e argila (malhas IV e VII) apresentaram potencial líquido positivo (não geradoras de acidez), indicando estarem livres de contaminação por sulfetos; (b) ambos os métodos de extração de solução do solo se mostraram equivalentes em termos de concentração de íons extraídos, conforme teste não paramétrico de Mann-Whitney; porém os diagramas de estabilidade mineral mostraram comportamento discrepante em função da maior atividade do Al na solução extraída com a pasta saturada em laboratório, mais diluída; (c) a solução do solo, por ambos métodos, confirmam a formação de drenagem ácida em profundidade, mesmo nas áreas com cobertura de terra vegetal ou argila (malhas IV e VII), indicando que essas camadas não são suficientes para conter ou minimizar o processo de geração de drenagem ácida; (d) na solução do solo foram encontrados valores acima do permitido para consumo humano para vários elementos (S, Cu, Zn, Fe, Mn, Cd, Cr, Ni, Pb, Se e As), como resultado do processo ativo de sulfurização, contrastando com a extração pelo método USEPA 3050, que indica somente valores acima para As e Se; (e) os estéreis de mineração dos solos construídos retém solução do solo com maior energia em relação às camadas superficiais (terra vegetal e argila) em função do caráter da porosidade dos estéreis, oriundo de processos litogênicos (diagênese), que aliada ao elevado potencial osmótico, reduz a quantidade de água disponível as plantas e (f) o monitoramento da variação da umidade do solo nos perfis dos solos construídos mostrou que as camadas de terra vegetal e de argila, em função da menor capacidade de retenção de água, mesmo quando saturadas, apresentaram menores níveis de umidade do solo ao longo do tempo do que as camadas mais profundas, compostas pelos estéreis de mineração. / The coal and associated rocks may contain pyrite, which undergoes oxidation, when in contact with air or water producing sulfuric acid. This acidity accelerates the dissolution of minerals from the soil and increase the concentration of heavy metals in the soil solution, creating the acid mine drainage which contaminates surface and subsurface waters. This study aimed to investigate the effect of acid mine drainage on the chemical properties and retention of the soil solution in constructed soil in coal mining area in Candiota, RS. Pits were opened and disturbed and undisturbed samples were collected at four depths (0-10, 40-50, 100-110, 190-200 cm) and suction lysimeters and humidity sensors were installed in soil constructed soil profiles of different ages and morphology (without topsoil: MII-T1 - 28 years; with topsoil: MIV-T1 - 18 years, MIV-T2 – 17 years, MVII-T3 - 10 years, MIV-T4 - 4 years). In the disturbed samples basic physical and chemical analysis were performed (particle size, pH (in water, CaCl2), SMP index, exchangeable cations, potential acidity and organic carbon), as well as metals extracted by the US-EPA3050 method, acidification (AP) and neutralization potential (PN) by the hydrogen peroxide method, and mineralogy, analyzed by X-ray diffraction in powder (total sample). In the field, suction lysimeters (Ecotech, Bonn, Germany), to collect soil solution, and moisture sensors (Watermark), to monitor the moisture, were installed. Soil solution were also extracted in the laboratory, by the saturated paste extract method. Metals and basic cations in soil solutions obtained by the two methods were analyzed by ICP-OES and Si and S determined by UV-visible spectroscopy and the results compared by nonparametric tests and mineral stability diagrams. Soil solution retention curves were determined with Richards chambers and by WP-4, and the available water capacity taking into account the osmotic potential. It was concluded that (a) all layers of mine overburden materials showed acidification potential while top soil and clay layers (MIV and MVII) had a positive net potential (non-acid generation), indicating the they were free from sulfides contamination; (b) both methods of extraction of soil solution showed to be equivalent in terms of concentration of extracted ions as analyzed by non-parametric Mann-Whitney test; but the mineral stability diagrams showed different behavior due to the higher activity of Al in solution extracted with saturated paste in the laboratory, more diluted; (c) the soil solution, by both methods, confirm the formation of acid drainage in depth, even areas covered by topsoil or clay layers (MIV MVII), indicating that these layers are not sufficient to contain or minimize the generation of acid mine drainage; (d) in soil solution values above the allowed for human consumption for various elements (S, Cu, Zn, Fe, Mn, Cd, Cr, Ni, Pb, Se and As) as a result of the active process of desulfurization were found, contrasting with the metals extracted by the USEPA 3050 method, that indicates that values above the allowed only to As and Se; (e) the overburden materials retain soil solution with higher energy than the topsoil and clay layers due to the character of their porosity, originated by lithogenic processes (diagenesis), which allied to the high osmotic potential, reduces the amount of plant available water and (f) the monitoring of the soil moisture in the constructed soil profiles showed that the topsoil and clay layers, due to the lower water holding capacity, even when saturated, showed lower levels of soil moisture over time than the deeper layers, composed by mine overburden.
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Étude de la lixiviation des Éléments Traces en zone non saturée : application à la réhabilitation des sites contaminés / Trace Elements leaching study in the unsaturated zone : application to the remediation of contaminated sites

Coutelot, Fanny 02 June 2014 (has links)
Ce travail contribue à l'acquisition des connaissances sur les mécanismes et les facteurs contrôlant le transfert des éléments traces dans le système sol-nappes d'eaux souterraines. Le nombre de plus en plus important de sols contaminés par les éléments traces potentiellement toxiques suite aux activités industries a reçu beaucoup d'attention au cours des deux dernières décennies. Les polluants accumulés dans ces sols peuvent alors être transférés dans différents compartiments de l'environnement en fonction de leur origine, leur spéciation et les conditions physico-chimiques et biologiques du milieu. Ainsi, une des problématiques est la pollution des nappes d'eau souterraine par ces éléments traces. Les flux massiques d'éléments traces dans les sols vers les nappes d'eau souterraines sont un paramètre d'entrée important pour prévoir le devenir des pollutions des aquifères et donc à évaluer le potentiel de la contamination des ressources en eau potable. L’objectif de cette thèse a été de proposer une méthode de mesure des flux en laboratoire qui permette de simuler au mieux les conditions naturelles des transferts des éléments traces vers les nappes. Pour cela, nous avons mis au point une colonne de laboratoire non-saturée. Cette colonne a été testée dans différentes conditions de lixiviation, comparée aux méthodes de lixiviations normées et testée en condition d’immobilisation des éléments traces lors de l’apport d’amendements. Dans un premier temps, la colonne de laboratoire permet de diminuer l’erreur sur l’estimation des flux. Elle permet des mettre en évidence des phénomènes de sorption, désorption et complexation des éléments traces sur les substrats, contrôlant ainsi les transferts verticaux.Dans un deuxième temps nous avons évaluer l’effet d’amendements minéraux sur la mobilité des éléments traces sur deux sols contaminés par des extractions chimiques. Nous avons ensuite étudié la lixiviation de ces éléments suite à l’apport d’amendements: de l’hydroxyapatite et de la Grenaille d’acier dans ces deux sols en utilisant les colonnes de sol développés précédemment. L'étude de la localisation des éléments traces sur les minéraux nouvellement formés suite à l'apport de ces amendements minéraux et leur interaction avec les constituants minéraux d'origine des sols (microscopie couplé à des spectromètres de fluorescence X) nous a permis de comprendre et de déterminer les réactions mis en jeu au cours de la lixiviation de ces éléments. Ainsi, l’apport d’hydroxyapatite (HA) et de Grenaille d’acier (GA) ont permis de diminuer significativement les concentrations en Cd, Zn dans les lixiviats. En revanche, l’apport de HA et GA aux sols augmente significativement la libération de As (dans le cas de HA) et Pb suite a l’apport de GA et HA. Les phases minérales porteuses de ces éléments traces, ont pu être caractériser et ainsi les mécanismes responsables de l’immobilisation ou du relargage ont pu être identifiés. / This work contributes to the knowledge of the mechanisms and factors controlling the transfer of trace elements, particularly in the soil- groundwater pathway. Extensive soil contamination with potentially toxic traces elements from various industries has in many industrialized countries received significant attention over the last two decades. Mass fluxes of trace elements in soils to groundwater are important input parameter for predicting the fate of pollution of aquifers and thus to assess the potential for contamination of drinking water resources. The objective of this study was to propose a method for measuring the fluxes in laboratory to simulate the natural conditions. For this, we have developed an unsaturated soil column. This column was then tested in various leaching conditions (compared to standardized leaching methods and tested under conditions of immobilization of trace elements). At first, the laboratory column reduces the error in the estimation of flux. And allows to highlight sorption, desorption and complexation of trace elements on the substrates. In a second step we evaluate the effect of mineral amendments on the mobility of trace elements in two contaminated soils (extraction), the study their location on the newly formed minerals (microscopy coupled with X-ray fluorescence spectrometers) and finally the leaching of these. The addition of hydroxyapatite (HA) and Steel Shot (GA) have significantly reduced the concentrations of Cd, Zn and As (in the case of the contribution of GA). In contrast, the addition of HA and GA in soils significantly increases the release of As (in the case of HA) and Pb following the addition of GA and HA). Mineral phases carrying these trace elements have been well characterized and the mechanisms responsible for the retention or release have been identified.
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The impact of canopy composition on the nutritional statusof an admixed spruce and beech forest at Solling,central Germany / Der Einfluss der Zusammensetzung des Kronenraums auf den Nährstoffstatus eines Fichten-Buchen Mischwalds im Solling

Hojjati, Seyed Mohammad 14 February 2008 (has links)
No description available.

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