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Evaluation of Sulfidic Materials in Virginia Highway CorridorsOrndorff, Zenah W. 09 October 2001 (has links)
Road construction through sulfidic materials in Virginia has resulted in localized acid rock drainage (ARD) that threatens water quality, fill stability, integrity of building materials, and vegetation management. The objectives of this study were: i) to develop a state-wide sulfide hazard rating map based on characterization of the geologic formations associated with acid roadcuts, ii) to estimate depth to sulfidic sediments in the Coastal Plain based on landscape relationships, and iii) to evaluate potential acidity testing procedures on diverse materials. Geologic formations associated with acid roadcuts were characterized by potential peroxide acidity (PPA) and S content, and grouped into four categories. Listed in order of increasing severity, these formations included: the Tabb Formation (Coastal Plain), the Lynchburg Group of the Ashe Formation (Blue Ridge), the Chesapeake Group and Lower Tertiary deposits (Coastal Plain), the Millboro shale, Marcellus shale, Chatanooga shale and Needmore Formation (Valley and Ridge), and the Quantico Formation (Piedmont). Evaluation of landscape parameters near Richmond, Virginia, indicated that the likelihood of encountering sulfidic materials within a given depth at a specific location was related to elevation and mapped soil types. Elevation and soil map units were assigned to risk classes to indicate the likelihood of encountering sulfides within a depth of 9 m. Comparison of PPA and S content for 296 diverse samples indicated that S may serve as a screening tool to evaluate materials without carbonates. Comparison of PPA and conventional Acid-Base Accounting (ABA) for 14 diverse samples indicated that PPA and ABA were highly correlated, with PPA yielding 0.60 to 0.95X the amount of acidity as ABA. Potential acidity by Soxhlet extraction and PPA were equivalent for 3 of 4 diverse samples. Average acidity and metal contents of leachate from Soxhlet extractors were correlated with acidity and metals of road drainage. Sulfide hazard analysis should be an essential step in the pre-design phase of highway construction and other earth-disturbing activities. / Ph. D.
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Atributos químicos de solos cultivados com arroz na região sul do Estado do Amazonas / Chemical Attributes of Soils Cultivated with Rice in Sounthern Region of Amazonas StateRadmann, Vairton 28 February 2011 (has links)
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Previous issue date: 2011-02-28 / Ao longo tempo de cultivo de arroz de terras altas na região sul do Estado do
Amazonas constata-se baixas produtividades atribuídas a vários fatores, dentre os
quais, atributos químicos de solo limitantes. No entanto, poucos estudos têm sido
realizados relacionados ao nível de fertilidade dos solos cultivados com arroz. O
presente estudo tem por objetivo avaliar os principais atributos químicos de 72
amostras de solos dos campos naturais cultivados, identificando as possíveis
limitações químicas bem como estabelecer relações entre os atributos do solo. Para
isto, foram coletadas 72 amostras de solos em campos naturais cultivados com
arroz, na profundidade de 0 a 20 cm (camada arável) abrangendo os municípios de
Humaitá, Manicoré, Novo Aripuanã e Canutama e determinados os teores de areia,
silte, argila, carbono orgânico, fósforo, potássio, sódio, cálcio, magnésio, alumínio,
cobre, manganês, zinco, ferro, acidez ativa e potencial, capacidade de troca de
cátions, saturação por bases e saturação por alumínio. Os resultados foram
submetidos a análise estatística descritiva e análise de regressão. Em geral, os
solos de campos naturais cultivados apresentam texturas areia, franco-siltosa e
franco-argilo-siltosa. São baixos os teores de potássio, cálcio, cobre, manganês e
zinco, altos teores de ferro, baixos e adequados teores de magnésio, teores de
fósforo muito baixo. Os teores são médios e adequados de matéria orgânica, baixo e
médio pH em CaCl2 e médio e adequado pH em água, capacidade de troca de
cátions com nível médio, adequado e alto, saturação por bases baixa e médio e a
saturação por alumínio alta e muito alta. O pH SMP foi eficiente para estimar a
acidez potencial e os teores de argila e carbono orgânico total são eficientes para
estimar a capacidade de troca de cátions dos solos de campos naturais cultivados
no sul do estado do Amazonas. As principais limitações químicas para o cultivo dos
solos são: elevada acidez potencial, baixa e média saturação por bases e muito
baixa disponibilidade de fósforo. / Over time Upland rice cultivation in southern Amazonas State has shown low
productivity attributed to several factors, among which chemical attributes of limiting
soils. However few studies about soil fertility under rice crop have been conducted.
This study aims to evaluate the main chemical attributes of 72 soil samples of
cultivated grasslands, identify possible chemical limitations, as well as establish
relationship between these soil attributes. Seventy-two soil samples at depth of 0 to
20 cm (top soil) were collected in grasslands planted with rice, including the
municipalities of Humaitá, Manicoré, Novo Aripuanã e Canutama. Distribution of
sand, silt, clay, organic carbon, phosphorous, potassium, sodium, calcium,
magnesium, aluminum, copper, manganese, zinc, iron contents were determined.
Active and potential acidity, cation exchange capacity, base saturation and aluminum
saturation were also established. The results were submitted to descriptive statistical
analysis and to regression analysis. As a general rule, soils of cultivated grasslands
have sandy, loamy silt and silt clay loam texture low potassium, calcium, copper,
manganese, and zinc content, high iron content, low and appropriate magnesium
content, very low phosphorous content. It was also achieved on that soils, medium
and appropriate organic matter content. Low and medium pH in CaCl2 and medium
and appropriate pH in water, cation exchange capacity in medium, to high levels, low
and medium base saturation, high and very high aluminum saturation. SMP pH was
efficient for estimating potential acidity; clay and total organic carbon are efficient for
estimating soil cation exchange capacity in grasslands planted in southern Amazonas
State. The main chemical limitations for soil cultivation are: high potential acidity, low
and medium base saturation and very low phosphorous availability.
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Substituição da adubação nitrogenada mineral pela cama de frango na sucessão aveia e milho / Replacement of mineral nitrogen by poultry litter in the succession oats and cornSantos, Loana Bergamo dos 30 March 2011 (has links)
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Previous issue date: 2011-03-30 / The constant search for sustainability of production systems have driven research to find alternatives to the problems arising from the intensification of production systems. In this context the present work was to study the effects of substitution of mineral nitrogen by chicken litter in oat and corn in succession and chemical characteristics of soil. Two experiments were conducted during the period from May 2009 to March 2010 in Oxisol area located at the experimental farm of the State University of Paraná, municipality of Rondon. The first test was conducted under a randomized complete blocks with eight treatments obtained from different combinations of chicken manure (applied in oat) and mineral N fertilization (applied in corn) and four replications. We studied the production of dry matter and nutrient accumulation in the straw of the oat crop, and yield components and yield of corn. In the second trial, after the corn harvest, we studied the chemical properties of soil under the design of randomized blocks in factorial scheme 8x3, with the eight combinations of fertilizer used in the first trial related to three depths of soil sampling (0 -5, 5-10 and 10-15 cm). Larger quantities of poultry litter in oat provided higher dry matter production and accumulation of N. All fertilization studied provided satisfactory average productivity for corn (8569 kg ha-1). The soil properties were changed with the use of poultry litter associated with mineral N fertilization. There was a decrease in pH, Ca, Mg, and increased the P, potential acidity, the cation exchange capacity and exchangeable Al with increasing proportions of poultry litter in relation to mineral N fertilization / A busca constante pela sustentabilidade dos sistemas de produção têm direcionado as pesquisas à buscar alternativas aos problemas oriundos da intensificação dos sistemas produtivos. Nesse contexto o presente trabalho teve como objetivo estudar os efeitos da substituição da adubação nitrogenada mineral pela cama de frango na cultura da aveia e do milho em sucessão e nos atributos químicos do solo. Foram conduzidos dois ensaios durante o período de maio de 2009 à março de 2010 em área de Latossolo Vermelho eutroférrico localizada na fazenda experimental da Universidade Estadual do Oeste do Paraná, município de Marechal Cândido Rondon. O primeiro ensaio foi conduzido sob o delineamento em blocos ao acaso com seis tratamentos obtidos a partir de combinações de quantidades crescentes de cama de frango aplicadas na aveia combinadas com a adubação nitrogenada mineral de cobertura aplicada no milho e quatro repetições. Estudou-se a produção de massa seca e acúmulo de nitrogênio pela cultura da aveia, e os componentes de produção e produtividade da cultura do milho. No segundo ensaio, após a colheita do milho, estudou-se os atributos químicos do solo sob o delineamento em blocos ao acaso em esquema fatorial 6X3, com as seis combinações de adubação utilizadas no primeiro ensaio associadas a três profundidades de amostragem do solo (0-5; 5-10 e 10-15 cm). A aplicação de cama de frango na cultura da aveia propiciou aumento da produção de massa seca e acúmulo de maior quantidade de N, enquanto a substituição de parte da adubação nitrogenada mineral pela cama de frango elevou os índices de produtividade da cultura do milho. Os atributos químicos do solo foram alterados pelos fatores estudados, ocorrendo a elevação dos teores de P, MO, Al trocável e acidez potencial, e redução do pH, K, Ca, Mg, soma de bases e saturação por bases.
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