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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.
201

Assessment of soil water movement and the relative importance of shallow subsurface flow in a near-level Prairie watershed

Ross, Cody 20 January 2017 (has links)
Near-level Prairie landscapes have received limited attention in hydrological research. For this thesis, hydrometric measurements and four tracing experiments were completed at three “riparian-to-stream” sites in the Catfish Creek Watershed (southeastern Manitoba) to enhance Prairie hydrology understanding. First, hydrologic state variables were examined to infer vertical and lateral water movement. Second, tracer data were analyzed to evaluate the relative importance of surface versus subsurface water movement. Results show that hydrologic state variables can be useful for inferring riparian-to-stream water movement. Tracer data also revealed that subsurface water movement can contribute significantly to streamflow during snowmelt- and rainfall-triggered events in the study watershed. This thesis demonstrated that subsurface flow is a significant runoff generation mechanism in Prairie landscapes, thus challenging surface water-focused conceptualizations and management strategies that are traditionally used. The findings summarized in this thesis will be critical to improve the performance of hydrological models when applied to the Prairies. / February 2017
202

Geofyzikální průzkum podzemních dutin na lokalitě Letonice / Geophysical survey of subsurface voids at locality Letonice

Bartášková, Lucie January 2015 (has links)
The Větrníky national nature reserve, located in the South Moravian region north of the village of Letonice, is one of the largest steppe reserves in Southern Moravia. This whole area is characterized by the presence of both stable and active landslides, and the occurrence of suffosion sinkholes has been monitored there in the long-term. The aim of the thesis was to investigate whether it was possible to observe subsurface phenomena, caused by the washing out of fine rock particles by ground water, by means of geophysical methods. This phenomenon is known as suffosion. The measurements took place in the areas where the suffosion manifestation was very distinctive, that is around two sinkholes that were visible on the surface. In order to identify the suffosion structural-geological causes and their manifestations at a given location, the gravimetric and electrical resistivity tomography (ERT) methods were used in the first stage of the research. Measured data was further processed and geologically interpreted. The gravimetric method has proved suitable when identifying rocks affected by suffosion, in which case we assume that their density is lower than the density of the surrounding rocks. Using the ERT method, it was possible, in the vertical profile, to distinguish the sandy-gravelly sediments...
203

Caracterização geoambiental e avaliação dos parâmetros que influenciam na mobilidade do HCH no meio poroso / Geoenvironmental characterization and assessment of parameters that influence the mobility of the HCH in porous medium.

Macedo, Letícia dos Santos 17 October 2014 (has links)
Este trabalho apresenta a caracterização geoambiental de solos de uma área contaminada, localizada no município de Santo André, Estado de São Paulo, Brasil. O objetivo foi determinar parâmetros experimentais para permitir o estudo de alguns aspectos do transporte do pesticida organoclorado Hexaclorociclohexano (HCH). A área de estudo contém células com cerca de 30.000 toneladas de um material contendo HCH em elevadas concentrações. As investigações de campo demonstram que há concentrações de HCH na água subterrânea. Em 2011, foram coletadas amostras deformadas e indeformadas de solo em quatro diferentes pontos superficiais da área contaminada, e posteriormente uma amostra composta da camada de solo de alteração de rocha (SAR), a fim de responder a questionamentos quanto à mobilidade do contaminante na área. A caracterização geoambiental, baseada em ensaios laboratoriais, foi realizada por meio das seguintes análises: análise granulométrica, limites de Atterberg, densidade específica, porosidade, umidade do solo, curva de retenção de água no solo, condutividade hidráulica, ensaio de adsorção, pH, condutividade elétrica, capacidade de troca catiônica (CTC), teor de matéria orgânica e teor de voláteis. O solo superficial da área é heterogêneo e a capacidade de adsorção dos solos analisados foi menor do que o esperado. Esta caracterização subsidiou o estudo de fluxo e transporte do HCH, por meio de simulação numérica, utilizando o programa Hydrus 1D. As simulações tiveram dois objetivos diferentes: no primeiro foi avaliado os resultados da simulação em comparação à situação atual no campo; no segundo foi avaliada a sensibilidade do transporte em função da alteração dos parâmetros obtidos experimentalmente Ks; Kd; s e (Van Genuchten); e dos parâmetros obtidos na literatura. Os resultados permitiram concluir que o modelo Hydrus 1D consegue representar a contaminação do HCH no solo. O parâmetro de degradação na água foi essencial para chegar em ordens de grandeza de concentrações próximas das identificadas em campo. Os parâmetros de degradação, difusividade, dispersividade e condutividade hidráulica são os que mais afetam os resultados finais de concentração do HCH na água subterrânea e, portanto, merecem atenção maior durante as futuras investigações. / This paper presents the geoenvironmental characterization of soils from a contaminated site, located in Santo André, São Paulo State, Brazil. The objective was to determine experimental parameters to allow the study of some aspects of transport of the organochlorine pesticide hexachlorocyclohexane (HCH). The study site contains trenches with about 30,000 tons of a material containing high concentrations of HCH. The site investigations show that there are HCH concentrations in groundwater. In 2011, disturbed and undisturbed soil samples were collected at four different surface points of the contaminated site, and then a sample of soil from rock alteration layer (SAR) was also composed for characterization in order to answer questions concerning the mobility of contaminant in the site. The environmental characterization based on laboratory tests, was performed by the following analyzes: grain size distribution, Atterberg limits, specific gravity, porosity, moisture content, water retention curve, hydraulic conductivity, pH, electrical conductivity, cation exchange capacity (CEC), organic matter content and volatile content. The surface soil of the area is heterogeneous and the adsorption capacity of the soils analyzed were lower than expected. This characterization allowed the study of flow and transport of HCH through numerical simulation using the Hydrus 1D software. The simulations had two different goals, the first was evaluated the simulation results compared to the current situation in the field. In a second step the sensitivity of transport due to the change of the parameters obtained experimentally Ks; Kd; s and (Van Genuchten); and parameters obtained from the literature. The results showed that the Hydrus 1D model simulates HCH contamination in soil. Water degradation parameter was essential to get orders of magnitude similar to those identified in field concentrations. The degradation, diffusivity, hydraulic conductivity and dispersivity parameters are those that most affect the final results of concentration of HCH in groundwater and therefore deserve more attention in future investigations.
204

Communautés fongiques de sédiments marins de subsurface : diversité, origine et rôle écologique / Fungal communities in deep subsurface sediments : diversity, origin and ecological role

Rédou, Vanessa 27 October 2014 (has links)
Au cours des vingt dernières années, les études sur les sédiments marins profonds ont révélé la présence et l'activité de communautés microbiennes inattendues. Il est maintenant formellement établi que la biosphère profonde héberge de nombreux représentants des domaines des Archaea et des Bacteria. Cependant,les micro-eucaryotes et plus particulièrement les champignons n’ont été que très peu étudiés dans ces écosystèmes singuliers. Dans ce contexte, des approches moléculaire et culturale ont été utilisées afin de caractériser la diversité des communautés fongiques des sédiments marins profonds en utilisant le bassin de Canterbury comme modèle d’étude. Les résultats principaux obtenus lors de ce travail de thèse sont les suivants : (i) L’approche moléculaire basée sur l’ADN a fourni la preuve directe que les communautés fongiques peuvent persister jusqu’à la profondeur record de 1740 mètres sous la surface du plancher océanique. (ii) Des approches complémentaires ciblant les ARNr et les ARNm ont permis de préciser leur activité métabolique et d’obtenir de premiers indices sur les fonctions de ces champignons à 350m sous la surface du plancher océanique, principalement liées à la croissance, à l’adaptation aux contraintes environnementales in situ et aux interactions entre communautés microbiennes. (iii) L’approche culturale a permis de constituer une collection de culture de 183 isolats fongiques avec des caractéristiques écophysiologiques témoignant leur capacité d’adaptation aux conditions in situ. (iv) Le potentiel biotechnologique des isolats obtenus a été estimé via la recherche de gènes impliqués dans la synthèse de métabolites secondaires et a permis de positionner cette collection d’organismes originaux comme une ressource d’intérêt biotechnologique potentiel. Ce travail qui témoigne de la persistance et de l’activité des communautés fongiques dans les sédiments marins profonds élargit notre vision de la diversité microbienne dans ces milieux et soulève des hypothèses sur le rôle écologique des champignons au sein de la biosphère profonde. / Over the past two decades, investigations on deep marine sediments have revealed the occurrenceand activity of unexpected microbial communities. Many representatives of Archaea and Bacteria were reportedbut micro-eukaryotes and especially fungal communities are still poorly studied in this ecosystem. In this underexplored context, molecular- and culture-based approaches were used to characterize the diversityof fungal communities in deep subsurface sediments using the Canterbury Basin as a model system. The main results of this work are: (i) The molecular DNA-based approach provided direct evidence that the fungal communities persist until the record depth of 1,740 meters below sea floor. (ii) Supplementary approaches targeting rRNA and mRNA revealed their metabolic activity and highlighted first hints into the fungal functions at350 meters below sea floor, mainly related to growth, adaptation to in situ environmental constraints andmicrobial interactions. (iii) The culture based approach allowed establishing a culture collection of 183 fungal isolates with ecophysiological characteristics indicating their ability to adapt to in situ conditions. (iv) This culture collection seems to represent a reservoir of secondary metabolites as many genes involved in secondary metabolites pathways were revealed. The fungal collection established may be considered as an untapped resource to explore for biotechnological applications. This work demonstrating the persistence and activity of fungal communities in deep subsurface sediments (i)broadens our view of microbial diversity in these environments and (ii) raises hypotheses about the ecologicalroles of fungi in the deep biosphere
205

Viabilidade técnica do emprego de sistemas tipo \"wetlands\" para tratamento de água cinza visando o reúso não potável. / Technical feasibility of employment of systems type \"wetlands\" for greywater treatment aiming reuse no potable.

Monteiro, Rodrigo Cesar de Moraes 03 August 2009 (has links)
A disparidade entre o crescimento populacional e a oferta de água potável apresenta grandes riscos de abastecimento em grandes centros urbanos. A utilização desse recurso em residências é diferenciada em uso potável e não potável. A utilização de água potável para finalidades menos nobres leva à escassez hídrica local em menor prazo, necessitando de busca de água cada vez mais longe, encarecendo o valor desse bem aos usuários. O uso não potável deveria ser suprido por fontes alternativas, como águas pluviais ou água de reúso. Em residências, muitas vezes o volume de água não potável é suprido pela produção de água cinza, necessitando de tratamento para que seu uso não ofereça riscos aos usuários. Sistemas de tratamento tipo wetlands podem ser uma alternativa economicamente viável em locais com disponibilidade de área, tendo como atrativos a independência de energia elétrica para o processo, ausência da necessidade de produtos químicos e forte apelo estético e ambiental. O presente trabalho visou avaliar a viabilidade técnica de sistemas tipo wetlands no tratamento de água cinza, determinando a remoção de material orgânico, a constante de remoção desse substrato, determinar as taxas de remoções de nitrogênio e fósforo e avaliar a eficiência na remoção de indicadores de contaminação fecal em um sistema tipo wetlands de fluxo subsuperficial horizontal cultivado em policultura. O sistema tipo wetlands apresentou remoção média de matéria orgânica próxima a 60% nos para os parâmetros DBO, DQO e COT, possibilitando: K20 DBO = 0,40; K20 DQO = 0,34; e K20 COT 0,30. As taxas de remoção de nutriente foram: 0,07g/m².d de fósforo total e 0,22g/m².d de nitrogênio kjeldahl total. A remoção média de indicadores de contaminação fecal foi de 56% para coliformes totais e uma média de 2,7x104 UFC/100mL e 94% para Escherichia coli com média de 4,6x101 UFC/100mL no efluente final. O efluente final do sistema tipo wetlands apresenta melhora na sua qualidade. / The disparity between population growth and supply of drinking water presents major risks to supply in large urban centers. The use of this feature in homes is different in non-potable and potable use. The use of drinking water for less noble purposes leads to local water shortages in less time, requiring the search of water each time further, the value of this expensive and users. The non-potable use should be supplied by alternative sources such as rainwater or water reuse. In homes, many times the volume of non-potable water is supplied by production of greywater, requiring treatment for their use does not offer risks to users. Systems of treatment like \"wetlands\" may be an economically viable alternative in locations where the availability of area, with attractions such as the independence of electric energy to the process, no need for chemicals and strong aesthetic appeal and environmental. This study aimed to evaluate the technical feasibility of such systems \"wetlands\" in the treatment of gray water, determining the removal of organic material, the constant removal of the substrate, determining the rates of removal of nitrogen and phosphorus and evaluate the efficiency in the removal of indicators of fecal contamination in a system like \"wetlands\" of horizontal subsurface flow grown in polyculture. The system type \"wetlands\" showed average removal of organic matter close to 60% in for the parameters BOD, COD and TOC, allowing: DBO K20 = 0.40; K20 DQO = 0.34 and K20 TOC 0.30. The rates of removal of nutrients were: 0.07 g / m².d of total phosphorus, and 0.22 g / m².d of total Kjeldahl nitrogen. The average removal of indicators of fecal contamination was 56% for total coliforms and an average of 2.7x104CFU/100mL and 94% for Escherichia coli with an average of 4.6x101CFU/100mL in the final effluent. The effluent end of the system as \"wetlands\" has improved its quality.
206

Viabilidade técnica do emprego de sistemas tipo \"wetlands\" para tratamento de água cinza visando o reúso não potável. / Technical feasibility of employment of systems type \"wetlands\" for greywater treatment aiming reuse no potable.

Rodrigo Cesar de Moraes Monteiro 03 August 2009 (has links)
A disparidade entre o crescimento populacional e a oferta de água potável apresenta grandes riscos de abastecimento em grandes centros urbanos. A utilização desse recurso em residências é diferenciada em uso potável e não potável. A utilização de água potável para finalidades menos nobres leva à escassez hídrica local em menor prazo, necessitando de busca de água cada vez mais longe, encarecendo o valor desse bem aos usuários. O uso não potável deveria ser suprido por fontes alternativas, como águas pluviais ou água de reúso. Em residências, muitas vezes o volume de água não potável é suprido pela produção de água cinza, necessitando de tratamento para que seu uso não ofereça riscos aos usuários. Sistemas de tratamento tipo wetlands podem ser uma alternativa economicamente viável em locais com disponibilidade de área, tendo como atrativos a independência de energia elétrica para o processo, ausência da necessidade de produtos químicos e forte apelo estético e ambiental. O presente trabalho visou avaliar a viabilidade técnica de sistemas tipo wetlands no tratamento de água cinza, determinando a remoção de material orgânico, a constante de remoção desse substrato, determinar as taxas de remoções de nitrogênio e fósforo e avaliar a eficiência na remoção de indicadores de contaminação fecal em um sistema tipo wetlands de fluxo subsuperficial horizontal cultivado em policultura. O sistema tipo wetlands apresentou remoção média de matéria orgânica próxima a 60% nos para os parâmetros DBO, DQO e COT, possibilitando: K20 DBO = 0,40; K20 DQO = 0,34; e K20 COT 0,30. As taxas de remoção de nutriente foram: 0,07g/m².d de fósforo total e 0,22g/m².d de nitrogênio kjeldahl total. A remoção média de indicadores de contaminação fecal foi de 56% para coliformes totais e uma média de 2,7x104 UFC/100mL e 94% para Escherichia coli com média de 4,6x101 UFC/100mL no efluente final. O efluente final do sistema tipo wetlands apresenta melhora na sua qualidade. / The disparity between population growth and supply of drinking water presents major risks to supply in large urban centers. The use of this feature in homes is different in non-potable and potable use. The use of drinking water for less noble purposes leads to local water shortages in less time, requiring the search of water each time further, the value of this expensive and users. The non-potable use should be supplied by alternative sources such as rainwater or water reuse. In homes, many times the volume of non-potable water is supplied by production of greywater, requiring treatment for their use does not offer risks to users. Systems of treatment like \"wetlands\" may be an economically viable alternative in locations where the availability of area, with attractions such as the independence of electric energy to the process, no need for chemicals and strong aesthetic appeal and environmental. This study aimed to evaluate the technical feasibility of such systems \"wetlands\" in the treatment of gray water, determining the removal of organic material, the constant removal of the substrate, determining the rates of removal of nitrogen and phosphorus and evaluate the efficiency in the removal of indicators of fecal contamination in a system like \"wetlands\" of horizontal subsurface flow grown in polyculture. The system type \"wetlands\" showed average removal of organic matter close to 60% in for the parameters BOD, COD and TOC, allowing: DBO K20 = 0.40; K20 DQO = 0.34 and K20 TOC 0.30. The rates of removal of nutrients were: 0.07 g / m².d of total phosphorus, and 0.22 g / m².d of total Kjeldahl nitrogen. The average removal of indicators of fecal contamination was 56% for total coliforms and an average of 2.7x104CFU/100mL and 94% for Escherichia coli with an average of 4.6x101CFU/100mL in the final effluent. The effluent end of the system as \"wetlands\" has improved its quality.
207

Caracterização geoambiental e avaliação dos parâmetros que influenciam na mobilidade do HCH no meio poroso / Geoenvironmental characterization and assessment of parameters that influence the mobility of the HCH in porous medium.

Letícia dos Santos Macedo 17 October 2014 (has links)
Este trabalho apresenta a caracterização geoambiental de solos de uma área contaminada, localizada no município de Santo André, Estado de São Paulo, Brasil. O objetivo foi determinar parâmetros experimentais para permitir o estudo de alguns aspectos do transporte do pesticida organoclorado Hexaclorociclohexano (HCH). A área de estudo contém células com cerca de 30.000 toneladas de um material contendo HCH em elevadas concentrações. As investigações de campo demonstram que há concentrações de HCH na água subterrânea. Em 2011, foram coletadas amostras deformadas e indeformadas de solo em quatro diferentes pontos superficiais da área contaminada, e posteriormente uma amostra composta da camada de solo de alteração de rocha (SAR), a fim de responder a questionamentos quanto à mobilidade do contaminante na área. A caracterização geoambiental, baseada em ensaios laboratoriais, foi realizada por meio das seguintes análises: análise granulométrica, limites de Atterberg, densidade específica, porosidade, umidade do solo, curva de retenção de água no solo, condutividade hidráulica, ensaio de adsorção, pH, condutividade elétrica, capacidade de troca catiônica (CTC), teor de matéria orgânica e teor de voláteis. O solo superficial da área é heterogêneo e a capacidade de adsorção dos solos analisados foi menor do que o esperado. Esta caracterização subsidiou o estudo de fluxo e transporte do HCH, por meio de simulação numérica, utilizando o programa Hydrus 1D. As simulações tiveram dois objetivos diferentes: no primeiro foi avaliado os resultados da simulação em comparação à situação atual no campo; no segundo foi avaliada a sensibilidade do transporte em função da alteração dos parâmetros obtidos experimentalmente Ks; Kd; s e (Van Genuchten); e dos parâmetros obtidos na literatura. Os resultados permitiram concluir que o modelo Hydrus 1D consegue representar a contaminação do HCH no solo. O parâmetro de degradação na água foi essencial para chegar em ordens de grandeza de concentrações próximas das identificadas em campo. Os parâmetros de degradação, difusividade, dispersividade e condutividade hidráulica são os que mais afetam os resultados finais de concentração do HCH na água subterrânea e, portanto, merecem atenção maior durante as futuras investigações. / This paper presents the geoenvironmental characterization of soils from a contaminated site, located in Santo André, São Paulo State, Brazil. The objective was to determine experimental parameters to allow the study of some aspects of transport of the organochlorine pesticide hexachlorocyclohexane (HCH). The study site contains trenches with about 30,000 tons of a material containing high concentrations of HCH. The site investigations show that there are HCH concentrations in groundwater. In 2011, disturbed and undisturbed soil samples were collected at four different surface points of the contaminated site, and then a sample of soil from rock alteration layer (SAR) was also composed for characterization in order to answer questions concerning the mobility of contaminant in the site. The environmental characterization based on laboratory tests, was performed by the following analyzes: grain size distribution, Atterberg limits, specific gravity, porosity, moisture content, water retention curve, hydraulic conductivity, pH, electrical conductivity, cation exchange capacity (CEC), organic matter content and volatile content. The surface soil of the area is heterogeneous and the adsorption capacity of the soils analyzed were lower than expected. This characterization allowed the study of flow and transport of HCH through numerical simulation using the Hydrus 1D software. The simulations had two different goals, the first was evaluated the simulation results compared to the current situation in the field. In a second step the sensitivity of transport due to the change of the parameters obtained experimentally Ks; Kd; s and (Van Genuchten); and parameters obtained from the literature. The results showed that the Hydrus 1D model simulates HCH contamination in soil. Water degradation parameter was essential to get orders of magnitude similar to those identified in field concentrations. The degradation, diffusivity, hydraulic conductivity and dispersivity parameters are those that most affect the final results of concentration of HCH in groundwater and therefore deserve more attention in future investigations.
208

Aspectos agronômicos e ambientais da irrigação com efluente de estação de tratamento de esgoto e aplicação de fosfogesso em sistema de produção de cana de açúcar / Agronomic and environmental aspects of irrigation with treated sewage effluent and phosphogypsum application on sugarcane production

Julius Blum 02 February 2012 (has links)
O uso de efluentes de estação de tratamento de esgoto (EETE) para a irrigação de culturas agrícolas é uma forma adequada de reciclagem de nutrientes e da água utilizada pelas populações urbanas, portanto, importante para o uso sustentável de recursos. Embora seja uma prática bastante antiga no mundo, no Brasil é ainda insipiente, pois as pesquisas relacionadas ao tema iniciaram-se por volta do ano 2000. Apesar de alguns resultados serem positivos do ponto de vista de sua utilização, ainda existem algumas dúvidas relacionadas ao (i) balanço de nutrientes para o manejo de fertilizantes com vistas à nutrição vegetal e à segurança ambiental, (ii) ao acumulo de sódio no solo em condições normais de irrigação e precipitação pluvial e possível amenização desse efeito e (iii) ao risco de acúmulo de nitrogênio no lençol freático. Com o propósito de responder a esses questionamentos, tratamentos com fosfogesso foram estabelecidos em cultura de cana de açúcar previamente irrigada com EETE onde foram avaliados: (i) nutrição das plantas; (ii) aporte e exportação de nutrientes; (iii) qualidade do solo principalmente no tocante ao sódio e propriedades relacionadas; (iv) fluxo de solução e nitrogênio através do solo. Após dois anos da aplicação de gesso e cinco anos consecutivos de irrigação com EETE as propriedades químicas do solo, especialmente aquelas relacionadas com a acidez do solo e cátions básicos, foram afetadas pela irrigação, mantendo o solo em condições adequadas para o desenvolvimento das plantas sem a necessidade de calagem. Os efeitos da aplicação de gesso sobre os teores de Ca, S e Na no solo foram mais pronunciados em curto prazo, sendo que não afetaram as propriedades físicas do solo após dois anos da aplicação. Entretanto, a alta concentração de Na+ e seus efeitos sobre propriedades físicas do solo revelaram-se naturalmente reversíveis em solo bem drenados com uma estação chuvosa. Nitrogênio, P, Ca e Mg tiveram concentrações adequadas no solo e na planta, principalmente nos tratamentos irrigados, sendo o EETE uma importante fonte desses nutrientes devendo estes serem considerados no manejo da fertilização. Embora o K e o S sejam fornecidos pela irrigação com EETE em quantidades suficientes para atender a demanda da cultura, a irrigação não melhorou a nutrição em relação a estes nutrientes mesmo em situações onde foi observada deficiência. A nutrição com Fe, Zn e Mn não foi relacionada ao fornecimento desses micronutrientes pelo EETE, mas sim ao aumento do pH do solo. O manejo da irrigação e fertilização foi critico em relação ao nitrogênio cujo aporte foi dessincronizado com a absorção pela cultura e lixiviado quando aplicado em excesso. Sendo que os modelos para a predição de sua lixiviação devem considerar N aportado, drenagem e precipitação. A propagação do erro das medidas do potencial da água no solo representou até 70% da variância do fluxo de nitrogênio através do solo. / Utilization of treated sewage effluent (TSE) to crop irrigation is a form of recycling the nutrients and the water used by urban populations, therefore, important for the sustainable use of resources. Although it is a very ancient practice in the world, is incipient in Brazil, where research on the topic began around the year 2000. Despite of some positive results from its use, there are still some questions related to (i) balance of nutrients for fertilizer management aiming plant nutrition and environment safety, (ii) accumulation of sodium in the soil under normal irrigation and rainfall conditions and possible mitigation of this effect and (iii) the risk of accumulation of nitrogen in groundwater. To answer these questions, gypsum treatments were established in sugarcane crop previously irrigated with TSE, where were evaluated: (i) plant nutrition, (ii) supply and removal of nutrients, (iii) soil quality mainly regarding to sodium related properties and (iv) flow of solution and Nitrogen through the soil. After two years of application of gypsum and five consecutive years of irrigation with TSE the soil chemical properties, especially those related to soil acidity and basic cations were affected by irrigation, keeping the soil in conditions suitable for the plants development without the need for liming. The effects of gypsum on Ca, S and Na in the soil were more pronounced in the short term evaluation, and did not affect the physical properties of soil after two years of application. However, the high concentration of Na+ and its effect on physical properties of the soil proved to be naturally reversible in well-drained soil with a rainy season. Nitrogen, P, Ca and Mg had adequate concentrations in soil and plant, mainly in the irrigated treatments, being the TSE an important source of these nutrients and those should be considered in the management of fertilization. Although the K and S are provided by irrigation with EETE in sufficient quantities to meet the crop demand, the irrigation did not improve the plant nutrition related to these nutrients even in situations where it was observed deficiencies of these nutrients in the leaves. The rapid movement of these nutrients in the soil or interaction with other ions is the possible causes of the lack of effect. Nutrition with Fe, Zn and Mn was not related to the input of these micronutrients by EETE, but was related to the increase in soil pH that is associated with decreased availability of these nutrients. The management of irrigation and fertilization was critical in relation with the nitrogen whose contribution was unsynchronized with the sugarcane uptake and it was leached when applied in excess. The models for the prediction of N leaching should consider accumulated input of N, drainage and precipitation. The propagation of the error from the measurements of the matric potential of the water in the soil represented up to 70% of the variance of the nitrogen flux through the soil.
209

Necessidade hídrica e produção do tomateiro para processamento industrial, em resposta a manejos e épocas de suspensão da irrigação / Water requirement and production of tomato for industrial processing in response to managements and times of irrigation suspension

Silva, Cícero José da 11 July 2017 (has links)
A água é um dos principais fatores que afeta o desenvolvimento, a produtividade e a qualidade industrial dos frutos de tomateiro. Assim, o objetivo deste trabalho foi quantificar durante dois anos a necessidade hídrica, desenvolvimento vegetativo e produtividade do tomateiro para processamento industrial (BRS Sena) em sistema de gotejamento enterrado, em resposta a níveis e épocas de suspensão da irrigação na região Sul de Goiás. Os experimentos foram instalados no delineamento em blocos ao acaso, com quatro repetições, em parcelas subdivididas. Nas parcelas foram aplicados cinco níveis de irrigação (50, 75, 100, 125 e 150% da evapotranspiração potencial da cultura - ETc), acumulada entre duas irrigações consecutivas. Nas subparcelas foram aplicados cinco períodos de suspensão da irrigação: 0, 7, 14, 21 e 28 dias, em antecedência à colheita. A subparcela experimental foi constituída por três linhas de plantas, de 5,5 m de comprimento, espaçadas em 1,1 m entre si e 0,30 m entre plantas. Utilizou-se o sistema de irrigação com tubo gotejador autocompensantes, com emissores espaçados de 30 cm entre si e vazão de 2,2 L h-1, com sistema antesifão, enterrado a 20 cm de profundidade. O deficit e o excesso hídrico prejudicaram o desenvolvimento vegetativo e a produtividade do tomateiro, reduziram o número de flores, frutos e aumentaram a taxa de abortamento de flores do cacho floral das plantas. As plantas cultivadas sob deficit hídrico, independentemente do período e ano de avaliação, apresentaram maiores índices de estresse hídrico da cultura (CWSI). Os níveis de irrigação em deficit e excesso prejudicam a produtividade do tomateiro. As maiores produtividades totais de frutos foram obtidas com reposições hídricas que variaram de 125,47 (615,09 mm) e 132,11% (564,00 mm) da ETc, que resultaram em uma produtividade total de frutos de 105,86 e 58,60 t ha-1, no primeiro e segundo ano do experimento, respectivamente. As plantas cultivadas sob deficit e excesso hídrico, aumentaram a incidência de frutos podres e diminuem a de frutos maduros. Irrigações que variaram de 115 a 125 % da ETc, aumentaram a taxa de maturação dos frutos, diminuiu a incidência de frutos verdes e podres. A maior produtividade da água obitida para a cultura ocorreu sob deficit hídrico, com reposição de 50% da irrigação necessária. A suspensão da irrigação em antecedência à colheita diminuiu a incidência de frutos verdes e aumentou a ocorrência de frutos podres. Quanto maior o período de suspensão da irrigação, menor a produtividade da cultura. Os níveis e suspensão da irrigação antes da colheita não influenciaram os valores de sólidos solúveis totais (SST), pH e firmeza. Porém, a acidez titulável apresentou maiores valores à medida que aumentou os níveis de irrigação na cultura Os coeficientes de cultivo do tomateiro foram estimados em aproximadamente 0,65, 1,01, 1,23, 1,25 e 0,80 em 2015. Enquanto em 2016 os valores de kc foram influenciados pelo menor desenvolvimento e produtividade das plantas, que foram afetadas com viroses influenciando e comprometendo os valores do kc. / Water is one of the main factors affecting the development, production and industrial quality of tomato fruits. Thus, the objectieve of this work was to quantify for two years the water requirement, vegetative development and tomato yield for industrial processing (BRS Sena) in buried drip system on response to levels and times of irrigation suspension in Goiás southern region. The experiments were installed under a randomized complete block design with four replications, in subdivided plots. On the plots were applied five irrigation levels (50, 75, 100, 125 and 150% of potential crop evapotranspiration - ETc), accumulated between two consecutive irrigations. In the subplots were applied five irrigation suspension periods: 0, 7, 14, 21 and 28 days in advance of harvest. Three plant lines constituted the experimental subplot with 5.5 m in length, spaced at 1.1 m apart and 0.30 m between plants. Was used an irrigation system with a self-compensating drip-tube, spaced 0.30 m apart and 2.2 L h-1, with an anti-drainage system, which was buried at 0.20 m depth. Deficit and the hydric excess impaired vegetative development and tomato productivity, reduced the number of flowers, fruits and increased the flowers abortion rate from plant flower bunch. Plants cultivated under water deficit, regardless the period and evaluation year, had higher crop water stress index (CWSI). Irrigation levels in deficit and excess damage the tomato yield. The highest total fruit yields were obtained with water replacement ranging of 125.47% (615.09 mm) and 132.11% (564.00 mm) of ETc, which resulted in a total fruit yield of 105.86 and 58.60 t ha-1, in the first and second year of the experiment, respectively. The plants cultivated under deficit and water excess, increased the rotten fruits incidence and declined that of mature fruits. Irrigations that varied from 115 to 125% of ETc, increased the fruits maturation rate, decreased the incidence of green and rotten fruits. The higher water yield by the crop occurs under the water deficit, with 50% replacement of irrigation required. The irrigation suspension in advance of harvest reduced the incidence of green fruits and increased the occurrence of rotten fruits. The larger suspension period of irrigation result in lower crop yield. The levels and irrigation suspension before harvest did not influence the values of ºBrix, pH and firmness. However, the titratable acidity showed higher values as the irrigation levels in the crop increased. Tomato crop coefficients (kc) were estimated at about 0.65, 1.01, 1.23, 1.25 and 0.80 in 2015. While in 2016 the values of kc were influenced by the lower development and productivity of plants, which were affected by the virus influencing and compromising the kc values.
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Identification of potential conservation practices and hydrologic modeling of the upper Iowa watershed

Rundhaug, Trevor Julian 01 August 2018 (has links)
In 2016 the Iowa Watershed Approach (IWA) was created to increase community resiliency against flooding, to develop hydrologic assessments that would identify strategies to reduce flooding, and to implement those strategies within nine identified watersheds that experienced flooding between 2011 and 2013. One of the nine watersheds was the Upper Iowa watershed located in northeast Iowa. This thesis focuses on the work that has been done to create a hydrologic assessment of the Upper Iowa watershed. The hydrologic assessment identifies potential conservation practices, creates a hydrologic model to assess the hydrologic cycle over the past ten years, and identifies strategies to reduce flooding within the watershed. Many potential agricultural conservation practices within the Upper Iowa watershed were identified and trends relating to the soil, land use, and topography were determined. In addition, a methodology to compare potential conservation practices with existing conservation practices actually in place was developed including a tool to estimate the size of grassed waterways to NRCS design guidelines. The comparison validated the methodologies used to identify potential practice placements, identified locations where potential practices could be implemented, and showed how stakeholder preferences influence conservation implementation. Additionally, a hydrologic model of the Upper Iowa watershed was developed, using the new Generic Hydrologic Overland-Subsurface Toolset model and calibrated to simulate the time period of 2007 through 2016. The model was evaluated against water balance ratios and performance statistics calculated from measured data. The model achieved Nash Sutcliffe Efficiency scores for streamflow above 0.7 and percent bias scores between ±12% for the three wettest years of 2008, 2013, and 2016. With the calibrated model, the benefits of continuous cover crop implementation were investigated under current conditions and under increased extreme precipitation intensity expected from climate change over the next half century. The results of this investigation determined that continuous cover crops increased evapotranspiration within the early half of the year creating more storage within the soil. Thus the flood risk from convective storms during the summer was lowered. In addition, the benefits from cover crops in terms of peak flow and volume reductions were cumulative increasing each consecutive year and were proportional to the percentage of cover cropped area. Lastly, a scenario using cover crops in a future extreme precipitation environment resulted in a reduction of peak discharge to current conditions. The results of this thesis will guide both future work within the Upper Iowa watershed and contribute to the knowledge of hydrologic planning and modeling within agricultural watersheds.

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