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Emprego da fluorescencia de raios X por dispersao de energia no estudo da dinamica da vinhaca no soloSIMABUCO, SILVANA M. 09 October 2014 (has links)
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Atributos químicos do solo de várzea tropical cultivado com arroz irrigado em razão do manejo do nitrogênio / Chemical attributes of tropical varzea soil cultivated with rice irrigated for nitrogen managementGonçalves, Gustavo de Melo Oliveira 29 July 2016 (has links)
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Previous issue date: 2016-07-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In the last years, due to the government effort, especially in the Tocantins State, there have been significante increase on flooded rice production areas. However, there are few studies about nitrogen sources and doses in that region, which could improve the nitrogen efficiency use and provide higher incomes for farmers. This study aimed to determine the effects of different sources and doses of nitrogen in flooded lowland soils in the pH, redox potential and the concentration of ions in the soil solution in order to obtain the economicallyand environmentally best mineral nitrogen source and dose. The samples were collected in the 2014/2015 season at the Embrapa Rice and Beans Experimental Field - Palmital Farm-, in a Dystric Gleysol. The design was a complete randomized blocks, with four replications, two sources of nitrogen (common urea and slow release urea), three nitrogen rates (30, 70, 150 kg ha-1), and a control, without any N application.Soil solution samples were collected weekly, during the flooded period in rice cultivation, BRS Catiana genotype. The pH analysis and Eh (redoxpotential) were immediately read, just after the soil solution sampling, in the field, and thenHCl (2M) acidified,, and immediately frozen for later analysis of the following ions: Ca, Mg, K, Fe, Zn, Mn, MOS, NO3- and NH4+. The sources used did not affect the release of nutrients dynamics to the soil solution. The anaerobic condition caused changes in the Eh and ions solubility in the soil solution. The doses applied changed Ca and MOS concentrations in solution, and the dose of 150 kg ha-1 N showed the highest values for both. / Nos últimos anos, devido incentivos do governo, especialmente no Estado do Tocantins, houve significante aumento em áreas de produção de arroz irrigado. No entanto, existem poucos estudos sobre fontes de nitrogênio e doses naquela região, o que poderia melhorar a eficiência de uso de nitrogênio e proporcionar maiores rendimentos para os produtores rurais. O presente trabalho teve como objetivo determinar os efeitos de diferentes fontes e doses de nitrogênio em solos de várzea inundados no pH, potencial redox e na concentração de íons da solução do solo, visando a obtenção da fonte e dose de fertilizante economicamente viável e ambientalmente sustentável. As amostras foram coletadas na safra 2014/2015 no Campo Experimental da Fazenda Palmital, da Embrapa Arroz e Feijão, em Gleissolo Háplico. O delineamento utilizado foi o de blocos casualizados com quatro repetições, sendo duas fontes de nitrogênio (ureia comum e ureia de liberação lenta), três doses de N aplicadas em cobertura (30, 70, 150 kg ha-1), e a testemunha absoluta, sem aplicação alguma de N. Foram coletadas amostras de solução do solo, semanalmente, durante o período de inundação no cultivo do arroz, cultivar BRS Catiana. As análises de pH e Eh (potencial de oxirredução) foram feitas logo após a coleta da solução do solo no campo, e então, acidificadas com HCl (2M), e imediatamente congeladas para posterior análise dos seguintes elementos: Ca, Mg, K, Fe, Zn, Mn, MOS, NO3- e NH4+. As fontes utilizadas não interferiram na dinâmica de liberação dos nutrientes para solução do solo. A condição de anaerobiose causou modificações no estado de oxirredução e alterou a solubilidade dos nutrientes na solução do solo. As doses aplicadas alteraram as concentrações de Ca e MOS na solução, sendo a dose de 150 kg ha-1 de N a dose que apresentou os maiores valores para ambos.
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Teores de água e solutos no solo: desempenho e sensibilidade do modelo Hydrus-1D / Water and solutes contents in soil: performance and sensitivity of Hydrus-1D modelRoque Emmanuel da Costa de Pinho 15 January 2010 (has links)
A preocupação com o destino de produtos químicos e água, aplicados ao solo, tem motivado vários pesquisadores a desenvolverem e aplicarem modelos teóricos, objetivando descrever os processos físicos envolvidos no transporte desses produtos no perfil do solo. Nesse sentido, a presente pesquisa teve como objetivo a aplicação do modelo Hydrus-1D para simulação do movimento da água e dos íons nitrato e potássio, em condições de laboratório, utilizando-se para tal colunas segmentadas preenchidas com dois tipos de solo não-saturado (Latossolo Vermelho Amarelo e Nitossolo Vermelho), bem como avaliar o desempenho e sensibilidade do referido modelo. Para a obtenção dos parâmetros de transporte de cada soluto, foram elaboradas as curvas de distribuição de efluentes (Breakthrough Curves BTC). Os parâmetros de transporte obtidos e as condições de contorno de cada ensaio foram inseridos no modelo Hydrus- 1D para realização das simulações. O desempenho do modelo foi avaliado com base nos parâmetros estatísticos: erro máximo, erro absoluto médio, raiz quadrada do erro médio normalizado, coeficiente de massa residual, coeficiente de determinação, eficiência e índice de concordância de Willmott. A sensibilidade do modelo foi avaliada conforme o método proposto por McCuen e Snyder (1986) e a análise foi aplicada aos parâmetros: fluxo de entrada, condutividade hidráulica do solo saturado, teor de água na saturação, alfa e n (parâmetros de ajuste da curva de retenção), coeficiente de distribuição e dispersividade. Os resultados experimentais mostraram que o deslocamento do íon nitrato acompanhou a frente de molhamento e em relação ao potássio, observou-se uma maior retenção nas camadas superficiais da coluna de solo, para ambos os solos. Pôde-se concluir que o modelo Hydrus-1D foi eficiente para simulações de deslocamento de potássio e água para ambos os solos estudados e mediante a utilização do modelo de equilíbrio para o transporte de solutos no solo, o modelo Hydrus-1D não foi eficiente para simular o deslocamento de nitrato, para ambos os solos. Os procedimentos experimentais para estimativa de parâmetros de transporte, como as curvas de distribuição de efluentes, foram suficientes para descrever a movimentação de potássio no solo, gerando informações de entrada precisas para os modelos de simulação. Para a simulação do deslocamento do íon nitrato, concluiu-se que o modelo Hydrus-1D requer um processo experimental mais detalhado, sendo necessária a estimativa de um maior número de parâmetros de transporte. Em relação à análise de sensibilidade, ao simular os teores de potássio e água no solo, o modelo apresentou maior sensibilidade aos parâmetros teor de água na saturação e fluxo de entrada da solução. Tais parâmetros, portanto, precisam ser determinados com maior precisão. Houve baixa sensibilidade aos parâmetros condutividade hidráulica do solo saturado e dispersividade, para ambos os solos estudados. / The concern about the fate of chemical products and water, applied to the soil, has been motivating several researchers to develop and apply theoretical models, aiming to describe the physical processes involved in the transport of those products in soil profile. The present research had as objective the application of the model Hydrus- 1D for water and solute (nitrate and potassium) simulation profile, in laboratory conditions, using soil columns filled with two types of unsaturated soil (Oxisol (Haplustox) and Hapludox), as well to evaluate the acting and sensitivity of the model. The transport parameters were obtained for each solute by breakthrough curves (BTCs). The transport parameters obtained and the boundary conditions were inserted in the Hydrus-1D model to realize the simulations. The acting of the Hydrus-1D model was evaluated using the statistical indicators: maximum error, mean absolute error, normalized root mean-square error, coefficient of residual mass, determination coefficient, efficiency and Willmott concordance index. The model sensitivity was evaluated by the method proposed by McCuen and Snyder (1986) and applied to the parameters: input flow, soil saturated hydraulic conductivity, water content (saturation point), alpha and n (soil water retention curve parameters), distribution coefficient and dispersivity. The obtained results, experimentally, showed the nitrate displacement following the wetting front and, in relation to the potassium ion, a larger retention was observed at the superficial soil columns layers. Therefore, was possible to conclude that Hydrus-1D model was efficient for both water and potassium displacement simulations, for both studied soils and by the balance model for solute transport in soil, the Hydrus- 1D model was not efficient to simulate the nitrate displacement in both soils. The experimental procedures to estimate transport parameters, by the BTCs, were enough to describe the potassium movement in soil, generating input information necessary to the model simulation. To the simulation of the nitrate displacement, was possible to conclude that the model Hydrus-1D requests a more detailed experimental process, being necessary the estimate of a larger number of transport parameters. In relation to the sensitivity analysis of the Hydrus-1D model, when simulated the content of potassium and water at the soil columns, was observed that the model shows more sensitivity about to the parameters: water content (saturation point) and input flow. This parameters need to be estimated with more precision. There was a low sensitivity to the parameters soil saturated hydraulic conductivity and dispersivity for both studied soils.
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Alkali Induced Heave In Kaolinitic Soils And Remedial MeasuresManju, * 06 1900 (has links) (PDF)
No description available.
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Distribuição e biodisponibilidade do níquel aplicado ao solo como NiCl2 e Biossólido. / Distribution and bioavailability of nickel applied to soil as nicl2 and biossólid.Tadeu Cavalcante Reis 10 March 2003 (has links)
O comportamento do Ni no solo, principalmente quando adicionado através de biossólidos, ainda é pouco conhecido. Este trabalho objetivou avaliar a influência dos teores totais do metal, de matéria orgânica e dos valores de pH na distribuição daquele elemento no solo e na sua biodisponibilidade. Foram conduzidos três experimentos de incubação em vasos mantidos em casa de vegetação, utilizando 3 kg de amostras da camada de 0 - 0,20 m de dois solos: ARGISSOLO VERMELHO AMARELO Distrófico (PVAd) e NITOSSOLO VERMELHO Distrófico Latossólico (NVdl). Dois experimentos foram montados em solos diferentes, em esquema fatorial 2x2x3, nos quais 2 doses de Ni (21 e 42 Kg ha 1 ) como NiCl2, foram incubadas durante 120 dias, sob dois teores de matéria orgânica e dois valores de pH, obtidos pela adição de turfa e de calcário, respectivamente. Num terceiro experimento fatorial (2x4), os mesmos dois solos foram incubados por 150 dias com a dose de 150 Mg ha -1 de quatro diferentes biossólidos. Posteriormente, cultivou-se alface em todos os vasos por 50 dias Após a incubação, amostras de solo foram analisadas quimicamente, inclusive efetuando-se extrações seqüenciais para determinar a distribuição do Ni adicionado através de NiCl2 e de biossólido. Foram consideradas as frações do metal solúvel + trocável, carbonatos, matéria orgânica, óxidos e residual. Realizou-se também a especiação do Ni baseada no equilíbrio de Donnan, no extrato de saturação das amostras, para discriminar a porção do Ni solúvel que se achava na forma de íon livre. O calcário foi o fator que mais afetou o comportamento do metal, reduzindo a concentração na fração trocável e aumentando-a nas frações matéria orgânica e óxidos. A turfa aumentou os teores do metal na fração trocável e os reduziu nas frações óxidos e matéria orgânica. O NiCl2 aumentou o teor de Ni nas três frações citadas. Os teores do metal nas frações de cada solo foram modelados por equações de regressão, em função dos teores de C-orgânico, Ni total e pH do solo. A distribuição do Ni no solo, quando adicionado através de biossólidos apresentou semelhanças com a distribuição do metal nos próprios biossólidos. Nestes casos, o Ni predominou nas frações mais fortemente retidas, conferindo ao metal comportamento distinto daquele observado pela adição do NiCl2. Tais diferenças puderam ser confirmadas pela ineficiência das equações obtidas nos experimentos com NiCl2, em predizer os teores do metal nas frações dos solos tratados com biossólidos. Na especiação, doses mais elevadas de calcário e turfa resultaram em menores teores de Ni solúvel e livre, os quais aumentaram com a dose de NiCl2. Concentração de ambas as formas de Ni se correlacionaram com os teores do metal absorvidos pelas plantas. Na aplicação de biossólidos ao PVAd, a determinação do Ni livre foi particularmente importante para se prever a biodisponibilidade de Ni para alface. Essencialmente, pode-se concluir que a extração seqüencial e a especiação em extrato de saturação foram eficientes para demonstrar diferenças do comportamento do níquel quando o metal foi aplicado como NiCl2 e como biossólido. / The role of Nickel in soils under the application of biossolids is still not very well known. The objectives of this study were to investigate the influence of total Nickel and organic carbon content, and soil pH, in the Nickel distribution among soil fractions and the bioavailability of the metal to lettuce. Three incubation pot trials were carried out in greenhouse placing in each one 3 kg of the 0-20cm layer of soil. Two soils types were considered: Typic Halpludult and Rhodic Kandiudox. In two of the trials, one for each soil type, soil samples were treated with rates of NiCl2, lime and peat as a source of organic matter and incubated during 120 days. In the third pot trial the above mentioned soils were incubated with four different types of biossolids during 150 days. Once the incubation period ended soils samples were collected and lettuce was planted in the pots of all three trials. Soils samples were submitted to a sequential extraction procedure which comprised the following fractions: exchangeable plus soluble; carbonate, organic, oxides and residual. Soil saturation extracts were also obtained for the determination of free Ni +2 concentration using the Donnan equilibrium technique. When NiCl2, peat, and lime were applied to soils, changes in pH due to lime caused exchangeable Ni to decrease and raised Ni content in organic and oxide fractions. Peat promoted an higher Ni content in the exchangeable fraction and reduced it in the oxide and organic fraction. I contrast NiCl2 raised Ni content in all of the above motioned fractions. Nickel content in all soil fractions were modeled by regression equations using total Ni, organic carbon, and pH as independent variables. Data for the Ni distribution in soils fractions under biossolids application were similar to results from sequential extraction in the biossolids in terms of percentage. In the biossolids trial Ni occurred most in residual fraction of soil, which contrasts with results obtained when Ni was supplied as NiCl2. Speciation study showed that higher rates of lime and peat promoted lower levels of soluble and free Ni in the soil solution. The opposite was detected when NiCl2 was applied. Both soluble Ni and free Ni +2 were well correlated with the Ni content in lettuce, when the metal salt was supplied as Ni source. However, free Ni +2 was a better indicator for Ni bioavailability when bissolids were applied in PVAd. In resume it may be concluded that the sequential extraction procedure and the speciation by means of the Donnan equilibrium approach were useful to express the different behavior of nickel in soil when NiCl2 or bissolids were the source of the metal.
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Avaliação do comportamento de elementos traço essenciais e não essenciais em solo contaminado sob cultivo de plantas / Evaluation of the behavior of essential and non essential trace elements in contaminated soil under plants cultivationMaria Ligia de Souza Silva 30 October 2006 (has links)
A contaminação do solo é crescente no mundo. Há grandes extensões de áreas contaminadas com elementos traço, compostos orgânicos, organometálicos e elementos radioativos, que ocorrem em concentrações que podem representar perigo ambiental. O comportamento dos elementos traço em solos e sua fitodisponibilidade com conseqüente passagem para a cadeia alimentar tem sido extensivo objeto de estudos mundialmente. Com o objetivo de avaliar o comportamento dos elementos traço, essenciais e não essenciais, num solo contaminado avaliou-se a absorção pelas plantas, a fitodisponibilidade por extratores e a fração do solo na qual os elementos encontram-se ligados em maior quantidade. O presente trabalho constou de dois experimentos, ambos realizados em casa de vegetação do Departamento de Ciência do Solo da ESALQ/USP com delineamento inteiramente casualizados, nos quais se utilizaram amostras de solo contaminado acidentalmente com elementos traço e espécies de plantas de interesse econômico. Os experimentos foram conduzidos de Novembro de 2004 a Abril de 2005, utilizando 7 níveis de contaminação por elementos traço e duas culturas, arroz e soja. Foi realizada adubação NPK de modo a atender as necessidades básicas de cada cultura. As plantas foram conduzidas até maturação. As variáveis avaliadas foram: desenvolvimento e produção vegetal; quantidade absorvida e acumulada de Cd, Cu, Fe, Mn, Pb e Zn; teores totais (água régia) e teores disponível dos elementos traço pelo uso das soluções Mehlich-1, HCl 0,1 mol L-1, DTPA e Ácidos Orgânicos no solo e a disponibilidade desses elementos através da correlação dos teores disponível no solo com os teores em folha diagnóstico, folha em final de ciclo e sementes de arroz e soja; e os teores de elementos traço nas frações do solo. A soja e o arroz foram sensíveis aos níveis de contaminação por elementos traço disponíveis no solo, exibindo sintomas de fitotoxidez, principalmente pelo Zn, manifestados por clorose e inibição do crescimento das plantas, sendo que o arroz mostrou-se mais sensível do que a soja à presença desses elementos. Para a soja, os quatro extratores foram eficientes para Cd, Cu, Pb e Zn, tanto ao correlacioná-los com teor na folha diagnóstico quanto na folha no final do ciclo enquanto que para o arroz, os mais eficientes foram o Mehlich-1, HCl 0,1 mol L-1 e o DTPA para o Cd, Cu, Fe e Zn. Para o Mn apenas o DTPA foi eficiente. Para o Fe, os extratores se mostraram pouco eficientes. O extrator Ácidos Orgânicos foi mais eficiente na avaliação da fitodisponibilidade de Cd, Cu, Pb e Zn para soja. Os maiores teores de Cd, Cu, Mn e Zn no solo encontram-se nas frações com ligações químicas mais estáveis (ligados a óxidos e residual) sendo as frações trocável + solúvel e orgânica de menor representatividade em relação ao total encontrado. O Pb, apesar de predominar nas frações ligadas a óxidos e residual, oferece grande potencial de contaminação ambiental por também apresentar-se nas frações trocável + solúvel e orgânica em teores consideráveis. O mesmo ocorre com o Zn, para o qual os teores totais foram mais elevados. / The contamination of the soil is growing in the world. There are great expanses of soil polluted with trace elements, organic compounds, organometals and radioactive elements that appear in concentrations that can endanger the environment. The behavior of trace elements in soils and its phytoavailability with subsequent transport to the alimentary chain has been quite intensive object of studies worldwide. With the objective of evaluating the behavior of essentials and non essential trace elements in a polluted soil, it was evaluated the absorption of trace elements by plants, its phytoavailability by extractors and in which fraction of the soil the elements are present in larger amount. The present work consisted of two experiments, both done entirely in a greenhouse of the Department of Soil Science of ESALQ/USP, with experimental design entirely randomized, in which samples of soil accidentally contaminated with trace elements and species of plants of economical interest were used. The experiments were conducted from November, 2004 to April, 2005, using seven levels of contamination for each trace elements and two cultures, rice and soybean. Fertilization with NPK was done in order to assist the basic needs of each culture. The plants were grown until maturation. The variables evaluated were: development and vegetable production; absorbed and accumulated amount of Cd, Cu, Fe, Mn, Pb and Zn; In the soil were determined total concentrations (HNO3/ HCl 1:3) and concentrations available of the trace elements by the use of the solutions Mehlich-1, HCl 0,1 mol L-1, DTPA and Organic Acids and the availability of those elements through the correlation of the available concentrations in the soil with the concentrations in diagnostic leaf, leafs in end of the cycle and seeds of rice and soybean; and the concentrations of trace elements in fractions of soil. The soybean and the rice were sensitive to the levels of trace elements available in the soil, exhibiting phytotoxicity symptoms, mainly for Zn, manifested as chlorosis and inhibition of growth. The rice was more sensitive than the soybean to the presence those elements. For soybean, the four extractors were efficient for Cd, Cu, Pb and Zn, both for the correlation with concentrations in the leaf diagnosis and in the leaf in the end of the cycle, while for rice, the most efficient were Mehlich-1, HCl 0,1 mol L-1 and DTPA for the Cd, Cu, Fe and Zn. For Mn, only DTPA was efficient. For Fe, the extractors were not efficient. The extractor Organic Acids was more efficient in the evaluation of the phytoavailability of Cd, Cu, Pb and Zn for soybean. The largest concentrations of Cd, Cu, Mn and Zn in the soil are found in the fractions with stable chemical bounds (attached to oxides and residue) being the exchangeable fractions + soluble and organic of smaller representativeness in relation to the total found. The Pb, in spite of prevailing in the fractions liked to oxides and residue, offers great potential of environmental contamination since it is also present in the exchangeable + soluble and organic fractions in considerable concentrations. The same happens for Zn, for which the total concentration was higher.
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Att stalla djuren hemma : Arkeologins motsägelsefulla bevis för järnålderns flerfunktionella långhusNors, Cajsa January 2020 (has links)
In this paper, I discuss the presence of farm animals in longhouses during the Iron Age in Sweden with some examples from Europe. Longhouses are often described as multifunctional housing. Though housing animals indoors has been questioned in the past, it remains a generally accepted interpretation. This paper aims to investigate if and how animals were housed inside and how archeologists in the future should work with the issue.
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Nähr- und Schadstoffdynamik flugaschebeeinflusster Waldböden der Dübener Heide: Ist-Zustand und PrognosenFritz, Heiko 18 October 2010 (has links)
In der vorliegenden Arbeit wurde die Nähr- und Schadstoffdynamik flugaschebeeinflusster Waldböden der Dübener Heide bezüglich ihres aktuellen Zustandes und der zu erwartenden zukünftigen Entwicklung untersucht.
In der Dübener Heide wurden jahrzehntelang große Mengen an Flugasche abgelagert, die die Eigenschaften des Bodens entscheidend und nachhaltig prägten. Selbst 15 Jahre nach dem abrupten Ende der Einträge kann eine Flugaschebeeinflussung noch immer deutlich nachgewiesen werden.
Das Ökosystem hat sich an die durch die Flugasche veränderten Umweltbedingungen angepasst. Nach Wegfall der Einträge unterliegt das System nun allerdings wieder neuen Veränderungen, deren Auswirkungen auf die Bestände noch unklar sind. Als Grundlage für nachhaltige forstliche Planungen und ein angepasstes Naturparkmanagement wurden deshalb im Rahmen des ENFORCHANGE-Teilprojektes Bodenprozesse der aktuelle bodenchemische Zustand der Dübener Heide untersucht und Prognosen über die zukünftige Entwicklung abgeleitet.
Für die Ermittlung des Ist-Zustandes wurden 12 Kernversuchsflächen ausgewählt, die entlang eines Entfernungsgradienten ausgehend vom angenommenen Hauptemittenten, Kraftwerk Zschornewitz, gelegen sind und die typischen Bodentypen und Bestände der Dübener Heide repräsentieren. 2 m tiefe Bodenprofile wurden angelegt und in Tiefenstufen beprobt. Die Bodenproben wurden mit Standardmethoden auf verschiedene bodenchemische Parameter untersucht.
Die Ergebnisse wurden sowohl hinsichtlich der Überschreitung von Mittel-, Vorsorge- und Grenzwerten als auch bezüglich der Ausbildung von Tiefen- und Entfernungsabhängigkeiten beurteilt. Darüber wurden die eindeutig flugaschebeeinflussten Parameter und die am stärksten beeinflussten Tiefenstufen identifiziert.
Diese Informationen wurden anschließend genutzt, um die Standorte statistisch in unterschiedlich stark flugaschebeeinflusste Gruppen einzuteilen.
Weiterhin wurden aktuelle Potentiale und Risiken abgeschätzt und über den Vergleich mit Literaturdaten die vergangene Entwicklung beurteilt.
Die Ergebnisse zum derzeitigen bodenchemischen Ist-Zustand der Dübener Heide können wie folgt zusammengefasst werden:
Als eindeutig flugaschebeeinflusst sind der pH-Wert, die Basensättigung sowie die Gesamtgehalte der Metalle Aluminium, Eisen, Calcium, Magnesium, Cadmium, Cobalt, Nickel und Zink identifiziert worden. Für diese bodenchemischen Parameter liegen klare, abnehmende Gradienten mit zunehmender Entfernung vom Hauptemittenten vor. So sind die pH-Werte im Mittel in den emittentennahen Auflagen um 1,5 pH-Einheiten höher als bei den emittentenfernen Auflagen. Während die emittentenfernen Auflagen dabei bereits etwa über den standorttypischen pH-Wert verfügen, sind die der nahen Standorte noch deutlich durch die Flugasche angehoben. Ebenso liegen in den Auflagen der emittentennahen Standorte sehr hohe Basensättigungen um 90 % und gegenüber den fernen Standorten um etwa 20 - 400 % höhere Metall-Gesamtgehalte vor.
Der pH-Gradient ist außerdem die Ursache dafür, dass Metalle mit pH-abhängigen Mobilitäten sehr deutlich ausgebildete Entfernungsgradienten in ihren verfügbaren Gehalten aufweisen, wobei die verfügbaren Gehalte im Gegensatz zu den Gesamtgehalten mit zunehmender Entfernung zum Emittenten ansteigen.
Anhand der Gesamtgehalte lässt sich nachweisen, dass die Flugaschebeeinflussung vor allem die Auflagen betrifft. Der Transport ganzer Flugaschepartikel in den Mineralboden wird anhand der vorliegenden Ergebnisse als unbedeutend angesehen. Dagegen erfolgt aber eine Verlagerung gelöster Flugaschebestandteile mit dem Sickerwasser. Diese führt dazu, dass ein flugaschebedingter Einfluss auf die pH-Werte, die Basensättigungen und die verfügbaren Gehalte der Basenkationen teilweise noch in 30 cm Tiefe feststellbar ist. Im tieferen Mineralboden überwiegen dann aber andere Standortfaktoren.
Für die Analyse des Flugascheeinflusses ist der Oh-Horizont am besten geeignet. Hier liegen die eindeutigsten und stärksten Gradienten von allen beeinflussten bodenchemischen Parametern vor. Der Of-Horizont ist dagegen bereits durch den Einfluss der Vegetation (Basenpumpe) teilweise überprägt.
Entsprechend der aktuellen Werte der eindeutig flugaschebeeinflussten Parameter lassen sich die Standorte zu drei unterschiedlich stark beeinflussten Gruppen zusammenfassen. Diese Gruppen spiegeln den Entfernungsgradienten wider und wurden deshalb als nahe, mittlere und ferne Standorte bezeichnet.
Die in der vorliegenden Arbeit gefundene Gruppierung weist aber Veränderungen gegenüber der anhand der Rauchschäden der Bestände vorgenommenen Einteilung der Dübener Heide in vier Rauchschadenszonen auf [LUX 1965b]. So wird heute der ehemals stark beeinflusste Standort Ochsenkopf-BDF (RSZ 1) nicht mehr den nahen, sondern den mittleren Standorten zugeordnet, während ein Teil ehemals mäßig beeinflusster Standorte (RSZ 3) mit früher gering geschädigten Standorten (RSZ 4) zu einer Gruppe zusammengefasst werden.
Ein Vergleich mit vorhandenen Literaturdaten zur Dübener Heide zeigt, dass die Unterschiede zwischen den Zonen (z. B. im pH-Wert) mit der Zeit mehr und mehr abnehmen und Nährstoffe (wie Calcium) langsam ausgewaschen werden. Bezüglich der Potentiale und Risiken kann angegeben werden, dass abgesehen von Cadmium, welches in der gesamten Dübener Heide erhöhte Werte aufweist, der Großteil der untersuchten Standorte über standorttypische mittlere Werte und Gehalte verfügt.
Nur an den nahen Standorten treten überdurchschnittlich hohe pH-Werte, Basensättigungen, Calcium-Gesamtgehalte und Vorsorgewertüberschreitungen bei den Gesamtgehalten von Cadmium und Zink auf. Die hohen pH-Werte dieser Standorte führen aber dazu, dass die mobilen Schwermetall-Gehalte derzeit noch niedrige Werte aufweisen und die positive Wirkung der verbesserten Nährstoffsituation überwiegt. Dabei nimmt der Standort Burgkemnitz eine Sonderrolle ein, da er selbst gegenüber dem ebenfalls nahen Standort Buchholz über extrem hohe Calcium-Gehalte und in Verbindung mit seiner sehr mächtigen Auflage auch über sehr hohe Elementvorräte verfügt.
Aufgrund der bereits zu beobachtenden Wiederversauerung und Abnahme der Calcium-Gehalte sind besonders für die nahen Standorte eine Verschlechterung der Nährstoffsituation und eine zunehmende Mobilisierung der Schwermetalle zu erwarten. Als Grundlage für die Abschätzung der Wirkung zukünftiger Veränderungen auf das Waldökosystem und die Bestände wurden deshalb Prognosen über die Entwicklung der relevanten flugaschebeeinflussten Parameter in den Auflagen der Dübener Heide aufgestellt. Mit Hilfe dieser Prognosen sollten sowohl das zu erwartende Ausmaß der Veränderung als auch deren zeitlicher Rahmen besser einschätzbar werden.
Für die Prognosen wurden Altdaten, aktuelle Messwerte und die Ergebnisse eines Freisetzungsexperimentes genutzt, um daraus Trends über die mittlere Entwicklung in den beim Ist-Zustand gefundenen Entfernungsgruppen ableiten zu können. Zusätzlich wurden die Einflüsse verschiedener, in der Prognose nicht berücksichtigter Faktoren diskutiert. Mit der vorliegenden Arbeit steht damit aus bodenchemischer Sicht erstmals ein umfassendes Werkzeug für die Bewertung zukünftiger Entwicklungen in der Dübener Heide zur Verfügung.
Die aufgestellten Prognosen lassen für die Auflagen der Dübener Heide die folgenden Aussagen zu:
Die pH-Werte werden weiter fallen, so dass sich bereits in wenigen Jahrzehnten signifikante pH-Unterschiede zwischen den mittleren und fernen Standorten nicht mehr feststellen lassen werden. Die nahen Standorte werden sich zwar noch am längsten durch erhöhte pH-Werte auszeichnen, aber in etwa 150 Jahren wird in der gesamten Dübener Heide wieder der standorttypische pH-Wert von etwa 3,0 vorliegen.
Verbunden mit der Abnahme der pH-Werte werden auch die Basensättigungen zurückgehen. Etwa 50 Jahre lang können die nahen Standorte noch als mindestens basenreich (> 50 % Basensättigung [AG-BODEN 2005]) angesehen werden. Gegen Ende des betrachteten Zeitraums von 150 Jahren ist dann mit einem einheitlichen Niveau der Basensättigung von ca. 20 % (Grenze zwischen mittelbasisch und basenarm [AG-BODEN 2005]) in den Auflagen der Dübener Heide zu rechnen.
Die Vorräte von Calcium und Magnesium werden nach und nach ausgetragen, wobei die Hauptursache dafür bei Calcium die Auswaschung aufgrund der Wirkung saurer Niederschläge, bei Magnesium der Ernteentzug ist. Mindestens 50 Jahre kann aber an den nahen Standorten noch von einer überdurchschnittlich guten Calciumversorgung ausgegangen werden. Stellenweise kann aber trotz der hohen Vorräte bereits in 30 Jahren die Magnesiumversorgung zum wachstumsbegrenzenden Faktor werden, da nur ein relativ kleiner Teil des Magnesiums freisetzbar zu sein scheint.
Bezüglich des Risikos nachteiliger Wirkungen aufgrund zu hoher verfügbarer Schwermetall-Gehalte sind nur Cadmium und Zink von Bedeutung. Die verfügbaren Gehalte dieser Schwermetalle werden im Zuge der Wiederversauerung ansteigen. Gleichzeitig erfolgt aber auch eine Auswaschung der Gehalte, die dem Anstieg der verfügbaren Gehalte und damit dem Überschreiten der Vorsorgewerte entgegenwirkt. Eine Gefährdung der Waldbestände ist demnach kaum zu erwarten. Die Toleranz der Bäume gegenüber Cadmium und Zink sollte aber trotzdem für langfristige waldbauliche Planungen berücksichtigt werden.:Danksagung 5
Erklärung 6
1 Einleitung und Zielsetzung 7
2 Das Untersuchungsgebiet Dübener Heide 10
2.1 Lage 10
2.2 Klima 11
2.3 Geologie und naturräumliche Gliederung 11
2.4 Boden 13
2.5 Emissionsgeschichte 13
2.6 Flugasche 17
2.6.1 Morphologische, physikalische und chemische Eigenschaften 18
2.6.2 Auswirkungen auf Boden und Pflanze 20
3 Material und Methoden 24
3.1 Charakterisierung der Standorte 24
3.1.1 Standortauswahl 24
3.1.2 Standort- und Profilbeschreibung 25
3.2 Probenahme, Probenvorbereitung 38
3.3 Standardlabormethoden zur Beurteilung des Ist-Zustandes 38
3.3.1 pH-Wert 38
3.3.2 Gesamtgehalte 39
3.3.3 NH4Cl-extrahierbare Gehalte 39
3.3.4 NH4NO3-extrahierbare Gehalte 39
3.4 Modelle und Experimente zur Ableitung von Prognosen 40
3.4.1 Extrapolation der zeitlichen pH-Wert-Entwicklung 40
3.4.2 Quantifizierung der pH-Abhängigkeit der Basensättigung 42
3.4.3 Quantifizierung der pH-Abhängigkeit der Mobilität 42
3.4.4 Berechnung der Säurefracht im Niederschlag 43
3.4.5 Experiment zur Prognose der Gesamtgehalte 44
3.4.6 Modell zur Prognose der verfügbaren Gehalte 50
3.5 Statistische Datenauswertung 52
3.5.1 Clusteranalyse 53
3.5.2 Diskriminanzanalyse 54
4 Ist-Zustand 57
4.1 Zielsetzung 57
4.2 Ergebnisse und Diskussion 57
4.2.1 pH-Wert 57
4.2.2 Makroelemente 62
4.2.3 Spurenelemente 75
4.2.4 Zusammenfassende Statistik 81
4.3 Schlussfolgerung 87
5 Prognosen 89
5.1 Zielsetzung 89
5.2 Ergebnisse und Diskussion 90
5.2.1 Zeitliche Entwicklung des pH-Wertes 90
5.2.2 Zeitliche Entwicklung der Basensättigung 96
5.2.3 Zeitliche Entwicklung der verfügbaren Gehalte (bei konstantem Gesamtgehalt) 99
5.2.4 Zeitliche Entwicklung der Gesamtgehalte 108
5.2.5 Zeitliche Entwicklung der verfügbaren Gehalte (bei abnehmendem Gesamtgehalt) 125
5.3 Schlussfolgerung 129
6 Zusammenfassung 132
7 Summary 136
8 Verzeichnisse 140
8.1 Literaturverzeichnis 140
8.2 Abbildungsverzeichnis 150
8.3 Tabellenverzeichnis 154
9 Anhang 156
9.1 Ist-Zustand 158
9.2 Prognosen 168 / In this study the dynamics of nutrients and pollutants within fly ash-affected forest soils of the Dübener Heide, Germany, were examined concerning their current state and the future development to be expected.
In the Dübener Heide large amounts of fly ash were deposited over decades, which had a crucial and lasting impact on the soil properties. Even 15 years after the abrupt end of the immissions this influence can still be proven.
The ecosystem has adapted itself to the environmental conditions changed by the fly ash. However, after the loss of further immissions the system is subject to changes once again with yet unknown consequences for the forest. As a basis for sustainable forest planning and an adapted nature park management the current soil-chemical state of the Dübener Heide was examined and prognoses for the future development were derived within the ENFORCHANGE subproject of soil processes.
For the determination of the current state 12 sites, that are representative for the typical soil types and stands of the Dübener Heide, were selected which have increasing distances to the coal-fired power plant Zschornewitz, regarded as the main emitter. Soil profiles, two meters in depth, were set up and sampled in depth stages. The soil samples were analyzed for different soil-chemical parameters by means of standard methods.
The results were judged regarding the exceeding of mean, critical and limiting values as well as the occurrence of dependencies on depth or distance. By that means parameters which are definitely influenced by the fly ash as well as the most strongly affected depth stages were identified.
These information were used afterwards in order to statistically divide the sites into groups of different grade of fly ash-affection.
Furthermore current potentials and risks were estimated, and the previous development was judged by comparison with literature data.
The results for the current soil-chemical state of the Dübener Heide can be summarized as follows:
The pH value, the base saturation and the total contents of the metals aluminium, iron, calcium, magnesium, cadmium, cobalt, nickel and zinc were identified as definitely fly ash-affected. Decreasing values of these soil-chemical parameters are clearly observable with increasing distance from the main emitter. So on average, the pH values of the forest floor horizons close to the emitter are greater by about 1.5 pH units than that of sites far from the emitter. Thereby the forest floor horizons far from the emitter already have approximately the typical pH value while pH values are sill raised by the fly ash at the closed-by sites. Very high base saturations around 90 % and total metal contents, that are higher by approximately 20 400 % compared with more distant sites are present in the forest floor horizons of sites close to the emitter, too.
In addition, the pH gradient is the cause for the fact that the available contents of metals with pH-dependent mobility exhibit very clearly formed distance gradients, with the available contents rising with the distance to the emitter contrary to the total contents of the metals.
By means of the total contents it can be proven, that the influence of the fly ash mainly concerns the forest floor horizons. The transport of whole fly ash particles into the mineral soil is regarded as insignificant on the basis of the available results. However, a displacement of solved fly ash components with seepage water takes place. This leads to the fact, that a fly ash-induced influence on the pH value, the base saturation, and the available contents of the base cations is partly detectable as far as 30 cm in depth. However, in still deeper mineral horizons different location factors predominate.
For the analysis of the fly ash influence the Oa-horizon is the most suitable. Here the clearest and strongest gradients of all affected soil-chemical parameters are present. The Oe-horizon is additionally marked in parts by the influence of the vegetation (base pump)
According to the current values of the definitely fly ash-affected parameters the sites can be divided into three groups with different grade of fly ash-affection. The distance gradients are reflected in these groups, and that is why the groups were termed closed-by, intermediate and distant sites.
However, the grouping found in the current study exhibits changes compared with the grouping of the Dübener Heide into the four smoke damage zones [LUX 1965b] according to the damage done to the stands by the smoke. Thus, today the formerly strongly affected site Ochsenkopf-BDF (RSZ 1) is no longer assigned to the closed-by but instead to the intermediate sites, while a part of the formerly moderately affected sites (RSZ 3) is now combined into one group together with formerly only slightly damaged site (RSZ 4).
A comparison with existing literature data from the Dübener Heide shows, that the differences between the zones (e.g. in pH value) decrease more and more with time, and that nutrients (like calcium) are slowly washed out. Concerning the potentials and risks it can be indicated that apart from cadmium, which exhibits increased values over the entire Dübener Heide, the majority of the examined sites has averaged values and contents typical for the location.
Only at the closed-by sites pH values, base saturations, total contents of calcium above the average and violations of limits of precaution of cadmium and zinc occur. But the high pH values at these sites lead to the fact, that the mobile heavy metal contents exhibit still low values at present, and that the positive effect of the improved nutrient situation predominates. The site Burgkemnitz takes a special position, since it has extremely high calcium contents and in connection with its very thick forest floor horizon also very high element stocks even in comparison with the likewise closed-by site Buchholz.
Due to the already observable acidification and the decrease in calcium contents a degradation of the nutrient situation and an increasing mobilization of the heavy metals are to be expected particularly for the closed-by sites. Therefore, as a basis for the estimation of the effect of future changes on the forest ecosystem and the stands prognoses for the development of the relevant fly ash-affected parameters in the forest floor horizons of the Dübener Heide were derived. With the help of these prognoses both the extent of the change to be expected and its time frame should become better assessable.
For the prognoses literature data, measured values of the current study and the results of a release experiment were used in order to be able to derive from it trends for the averaged development within the different groups of sites found for the current state. Additionally the influences of different factors not considered for the prognoses were discussed. So with this, for the first time there is available a comprehensive tool for the evaluation of future developments in the Dübener Heide from soil-chemical point of view.
The set up prognoses allow the following statements for the forest floor horizons of the Dübener Heide:
The pH values will continue to fall, so that already in a few decades significant pH differences between the intermediate and the distant sites will not be determinable any more. The longest time the closed-by sites will be characterised by increased pH values, but in approximately 150 years a location typical pH value of about 3.0 will be present over the entire Dübener Heide again.
Connected with the reduction of the pH values the base saturation will decrease, too. About 50 more years the closed-by sites can still be regarded as at least base rich (> 50 % base saturation [AG-BODEN 2005]). But towards the end of the considered time of 150 years it has to be reckoned on a uniform level of the base saturation of approximately 20 % (threshold between medium-basic and base-poor [AG-BODEN 2005]) in the forest floor horizons of the Dübener Heide.
The stocks of calcium and magnesium will be gradually decreased, for what the main cause is leaching due to the effect of acid precipitations for calcium and harvest removal for magnesium. At least for 50 more years it can be assumed that the closed-by sites will have a calcium supply good above average. In parts, however, despite the high stocks the magnesium supply can already become the growth-limiting factor in 30 years, since only a relative small part of magnesium seems to be available for leaching.
Only cadmium and zinc are of importance concerning the risk of unfavourable effects caused by too high contents of mobile heavy metals. The available contents of these heavy metals will rise as the result of increasing acidification. But at the same time leaching of the metals takes place what counteracts the rise of the available contents and thus the violation of the limits of precaution. According to this an endangerment of the forest stands is hardly to be expected. However, for long-term forest-structural planning the tolerance of the trees with respect to cadmium and zinc should be considered nevertheless.:Danksagung 5
Erklärung 6
1 Einleitung und Zielsetzung 7
2 Das Untersuchungsgebiet Dübener Heide 10
2.1 Lage 10
2.2 Klima 11
2.3 Geologie und naturräumliche Gliederung 11
2.4 Boden 13
2.5 Emissionsgeschichte 13
2.6 Flugasche 17
2.6.1 Morphologische, physikalische und chemische Eigenschaften 18
2.6.2 Auswirkungen auf Boden und Pflanze 20
3 Material und Methoden 24
3.1 Charakterisierung der Standorte 24
3.1.1 Standortauswahl 24
3.1.2 Standort- und Profilbeschreibung 25
3.2 Probenahme, Probenvorbereitung 38
3.3 Standardlabormethoden zur Beurteilung des Ist-Zustandes 38
3.3.1 pH-Wert 38
3.3.2 Gesamtgehalte 39
3.3.3 NH4Cl-extrahierbare Gehalte 39
3.3.4 NH4NO3-extrahierbare Gehalte 39
3.4 Modelle und Experimente zur Ableitung von Prognosen 40
3.4.1 Extrapolation der zeitlichen pH-Wert-Entwicklung 40
3.4.2 Quantifizierung der pH-Abhängigkeit der Basensättigung 42
3.4.3 Quantifizierung der pH-Abhängigkeit der Mobilität 42
3.4.4 Berechnung der Säurefracht im Niederschlag 43
3.4.5 Experiment zur Prognose der Gesamtgehalte 44
3.4.6 Modell zur Prognose der verfügbaren Gehalte 50
3.5 Statistische Datenauswertung 52
3.5.1 Clusteranalyse 53
3.5.2 Diskriminanzanalyse 54
4 Ist-Zustand 57
4.1 Zielsetzung 57
4.2 Ergebnisse und Diskussion 57
4.2.1 pH-Wert 57
4.2.2 Makroelemente 62
4.2.3 Spurenelemente 75
4.2.4 Zusammenfassende Statistik 81
4.3 Schlussfolgerung 87
5 Prognosen 89
5.1 Zielsetzung 89
5.2 Ergebnisse und Diskussion 90
5.2.1 Zeitliche Entwicklung des pH-Wertes 90
5.2.2 Zeitliche Entwicklung der Basensättigung 96
5.2.3 Zeitliche Entwicklung der verfügbaren Gehalte (bei konstantem Gesamtgehalt) 99
5.2.4 Zeitliche Entwicklung der Gesamtgehalte 108
5.2.5 Zeitliche Entwicklung der verfügbaren Gehalte (bei abnehmendem Gesamtgehalt) 125
5.3 Schlussfolgerung 129
6 Zusammenfassung 132
7 Summary 136
8 Verzeichnisse 140
8.1 Literaturverzeichnis 140
8.2 Abbildungsverzeichnis 150
8.3 Tabellenverzeichnis 154
9 Anhang 156
9.1 Ist-Zustand 158
9.2 Prognosen 168
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An Investigation of Fertilizer-Derived Uranium in Ohio Agricultural SoilsCalero, Adolfo Eberhard 29 September 2020 (has links)
No description available.
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Geological and Geochemical Controls on Non-Tuberculous Mycobacterium Transmission: Examples from HawaiiRobinson, Schuyler Thomas 01 June 2019 (has links)
The opportunistic environmental microbes, non-tuberculous Mycobacterium (NTM), pose an increasing risk of disease and death in both immunodeficient and immunocompetent individuals in the USA and across the world. NTM lung disease is particularly prevalent in Hawaii, although the modes of NTM acquisition and transport in Hawaii are not fully understood. This study evaluated 149 soil and 50 water samples across the Hawaiian Islands to determine geochemical factors controlling NTM. Non-metric multidimensional scaling (NMDS) and principal component analyses (PCA) of modern soils show variables such as Total Organic Carbon (TOC), pH, P, mafic silicate minerals, and Pb seem to control NTM presence and transition metals and oxides such as TiO2, Zr, and Nb seem to control the absence perhaps due to toxicity. Logistic regression modeling coupled with Kolmogorov-Smirnov testing supported that TOC and P could be used to explain the probability of NTM presence in modern soils. Kolmogorov-Smirnov, non-metric multidimensional scaling, and principal components analysis results suggest poor predictability of NTM presence in soils when evaluating mineralogy alone. The same statistical methods indicated that transition metals appeared to control NTM presence in stream water and major cations and anions seemed to control NTM absence. However, additional bacterial stream data is needed to strengthen this finding. Additionally, an Oahu source water assessment and protection groundwater model was refined by including stream discharge data, including losses to the aquifer. NTM inhabits many environmental niches, although little is understood regarding the transport of NTM from the environment to indoor plumbing. However, transport from surface water to water-supply aquifers is likely important. This study analyzes groundwater flow from stream losses as a mechanism of NTM transport to water supplies. An updated MODFLOW groundwater model was developed for the north-east Oahu, Waimea River drainage. Results show hundreds of meters of lateral and tens of meters of vertical transport of NTM in 1-3 months. Additionally, geochemical modeling with Geochemist’s Workbench showed Fe oxy/hydroxides oversaturated in 100% of streams. Fe oxy/hydroxide affixed to NTM would potentially satisfy NTM’s preference for attachment and allow for colloidal transport through the aquifer.
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