936 resultados para Uréia como fertilizante


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The therapeutic use of medicinal plants has contributed since antiquity in a beneficial way for health. However, many species lacks of scientific evidence which provide basis for their use in therapeutic practice. In this context is the Genipa americana L. species (Rubiaceae), popularly known as jenipapo and used to treat syfilis, ulcer and hemorrhagic disturbs. It's also used against bruising, as tonic and as aphrodisiac. Due this species lacks toxicological studies, the aim of this study was to evaluate the toxicity in vivo (acute and sub-chronic toxicity) and in vitro (cytotoxicity) of the hydroethanolic extract from G. americana fruits. The hydroethanolic extract of G. americana fruits was prepared by maceration. A preliminary phytochemical analysis was performed to assess the presence of secondary metabolites in the extract. The cytotoxicity study of the extract (0.1, 1.0, 10, 100 and 1000 mg / 100 ul) were performed against normal cells (3T3) and tumor (786-0, HepG2 and B16), analyzed by the MTT assay. To evaluate the acute (single dose of 2000 mg / Kg) and subchronic (100, 500 and 1000 mg / kg for 30 days) toxicity Swiss mice of both sexes were used. At the end of the experiment, blood samples and organs were collected for analysis. Data between groups were compared by t test or ANOVA with Dunnett's post-test with 5% significance level. The phytochemical study of the extracts mainly indicated the presence of iridoids. Results for cytotoxicity tests showed up to 70% inhibition of B16 cell line at a dose of 1000 mg / 100 ul, and up to 29% inhibition of 786-0 at a dose of 10 ug / 100 ul. The extract did not cause death in 3T3 and HepG2 cells. During the in vivo assays, there were no animal deaths. Analysis of blood samples revealed that the animals submitted to the evaluation of acute toxicity had changes in AST and ALT, and that the animals evaluated for subchronic toxicity showed changes in the relative wet weight of the kidney and plasma urea concentration. No differences were observed between groups on histopathological evaluation of the collected organs. Despite the changes found in the in vivo toxicity tests, using the criteria described by the OECD Guidelines, it is suggested that the hydroethanolic extract of the fruits of the G. americana is classified as low toxicity. The cytotoxicity of the extract suggests that they have potential against melanoma cell lines (B16).

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O azoto é determinante na produtividade e na qualidade da batata para indústria. Com este trabalho pretendeu-se avaliar o efeito de diferentes doses de azoto na variedade de batata “Hermes”, em plena condições de cultivo do Vale do Tejo. Os tratamentos consistiram na aplicação de 0 (N0), 80 (N80), 160 (N160), 240 (N240) e 320 (N320) kg de azoto/ha, na forma de ENTECÒ 26. O ensaio foi instalado em parcelas totalmente aleatórias, com 4 repetições. Foi registado semanal a taxa de cobertura de solo pelo método da grelha até à sua cobertura total. Bissemanalmente, foram recolhidas plantas nos tratamentos N0 (0kgN/ha) e N160 (160kgN/ha) para avaliação do seu desenvolvimento e crescimento. No final do ciclo cultural avaliou-se a produção total, comercial, em peso e número de tubérculos. Avaliou-se ainda o peso específico, os teores em matéria seca dos tubérculos e a percentagem do azoto total na matéria seca das folhas e tubérculos. A adubação azotada influenciou a dimensão do aparelho fotossintético, através do estímulo de ramificações. Verificou-se uma maior produtividade de tubérculos nos tratamentos com maior aplicação de azoto, embora os acréscimos tenham sido menores a partir dos 160kg/ha. O azoto influenciou a percentagem de tubérculos de maior calibre.

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Potato crop cycle is relatively short and presents high yield per area; therefore, it is a very demanding culture for available nutrients in the soil solution. Despite its importance and the large number of studies about the crop, there is little research on plant nutrition regarding the use of organomineral fertilizer. This study evaluated potato, cv. Cupid, development and productivity as a function of fertilization with pelletized organomineral fertilizer. The experiment was done in Perdizes, Minas Gerais, in the rainy season of 2014/2015. The experimental design was a randomized blocks, with factorial arrangement of 4 x 2 (doses x management) and a control with mineral fertilizer, with 3 repetitions. Organomineral fertilizer doses were 25, 50, 75 and 100% of the conventional mineral dose, which was 600 kg ha-1 K2SO4, 850 kg ha-1 NH4H2PO4, and 300 kg ha-1 (NH4)2SO4 of topdressing 19 days after planting (DAP). Fertilization managements were with or without topdressing at 19 DAP, when the potato was hilled. Two plants per plot were sampled at 36, 50, 64 and 81 DAP and analyzed for leaf, stem and dry matter contents. DRIS - Diagnosis and Recommendation Integrated System was applied at 36 DAP and the potatoes were harvested 112 DAP and subjected to tuber classification. Throughout the cycle, stem, leaf and tuber dry mass showed no significant differences between the fertilization managements. The doses of organomineral fertilizer and topdressing management does not affect productivity, and the lower doses (25%) were similar the greater ones and the control, with an average of 16.8 t ha-1, demonstrating that it is viable to make a single application of organomineral fertilizer at planting due to operational efficiency. The low yields observed were due to high rainfall and temperature, creating favorable conditions for the incidence of pests and diseases. According to DRIS, the organomineral dose 75% for topdressing, presented the best nutritional balance.

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Campomanesia adamantium and Campomanesia pubescens are morphologically similar, occur in the same regions of the Cerrado, are difficult to differentiate and exhibit naturally slow growth and development. The objectives of this study were to analyze fruit and seed biometric data, emergence capacity and seedling growth characteristics. Fruit from both species was collected and used to measure biometric data of the fruit and seeds and to set up two emergence and two seedling growth experiments. C. adamantium fruit is round and has wider, pale yellow seeds while C. pubescens fruit is ellipsoidal to pyriform with yellow gold seeds. C. adamantium’s greater fresh fruit mass and biometric variability favors selection of promising material for commercialization. Seed drying reduced the speed and rate of seedling emergence of C. adamantium, but had no effect on C. pubescens. Leaf number, height, shoot dry weight and the ratio of shoot dry weight to root dry weight were greater in C. adamantium than in the slower growing C. pubescens. Increases in substrate volume favor seedling development. Slow-release fertilizer application at 1g per 115 cm3 substrate increased leaf formation, plant height and shoot dry weight of seedlings of both species and lateral budding in C. adamantium. Until 120 days after transplant, lateral budding was not observed in C. pubescens seedlings. For all traits evaluated in this experiment, C. adamantium seedling growth was greater than that of C. pubescens.

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[EN]Aeolian dust plays an important role in climate and ocean processes. Particularly, Saharan dust deposition is of importance in the Canary Current due to its content of iron minerals, which are fertilizers of the ocean. In this work, dust particles are characterized mainly by granulometry, morphometry and mineralogy, using image processing and scanning northern Mauritania and the Western Sahara. The concentration of terrigenous material was measured in three environments: the atmosphere (300 m above sea level), the mixed layer at 10 m depth, and 150 m depth. Samples were collected before and during the dust events, thus allowing the effect of Saharan dust inputs in the water column to be assessed. The dominant grain size was coarse silt

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[EN] Aeolian dust plays an important role in climate and ocean processes. Particularly, Saharan dust deposition is of importance in the Canary Current due to its content of iron minerals, which are fertilizers of the ocean. In this work, dust particles are characterized mainly by granulometry, morphometry and mineralogy, using image processing and scanning northern Mauritania and the Western Sahara. The concentration of terrigenous material was measured in three environments: the atmosphere (300 m above sea level), the mixed layer at 10 m depth, and 150 m depth. Samples were collected before and during the dust events, thus allowing the effect of Saharan dust inputs in the water column to be assessed.

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The ability of SnCl2.2H2O as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, ethyl acetoacetate and urea or thiourea is described. The reaction was carried out in acetonitrile or ethanol as solvents in neutral media and represents an improvement of the classical Biginelli protocol and an advantage in comparison with FeCl3.6H2O, NiCl2.6H2O and CoCl2.6H2O which were used with HCl as co-catalyst. The synthesis of 3,4-dihydropyrimidinones was achieved in good to excelent yields.

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Existen distintos enfoques para abordar la nutrición con P y, en la actualidad, muchos de ellos coexisten sin estar definidos claramente cuál es su objetivo. En la región pampeana norte de Argentina no se encuentra disponible una herramienta que integre la información disponible y permita realizar una recomendación de fertilización con P en el cultivo de maíz. Se decidió integrar los diferentes resultados científicos publicados para desarrollar una herramienta que ayude en la toma de decisiones de un plan de fertilización con P, teniendo en cuenta no solo las cuestiones agronómicas, una u otra filosofía, sino también las condiciones económicas y empresariales. Se desarrollaron ecuaciones en base a esa información científica y ajustes para que el calculador tuviese además un entorno sencillo de manejo y cálculos económicos para evaluar rentabilidad en función del criterio de aplicación de P seleccionado. Con las funciones proporcionadas por las fuentes consultadas se construyó un Calculador de P que estima la dosis de fertilizante a utilizar según el nivel actual de P Bray1 del suelo y el criterio de fertilización que se desee utilizar. De acuerdo a la función ajustada, se requiere un valor de P-Bray1 de 20 ppm, para que este nutriente no limite el rendimiento. Las bases de funcionamiento de la herramienta radican en información publicada, la cual puede ser revisada por cualquier interesado en el tema ya sea para perfeccionar la herramienta y generar un modelo superador o para interpretar lo realizado

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The ability of SnCl2.2H2O as catalyst to promote the Biginelli three-component condensation reaction from a diversity of aromatic aldehydes, ethyl acetoacetate and urea or thiourea is described. The reaction was carried out in acetonitrile or ethanol as solvents in neutral media and represents an improvement of the classical Biginelli protocol and an advantage in comparison with FeCl3.6H2O, NiCl2.6H2O and CoCl2.6H2O which were used with HCl as co-catalyst. The synthesis of 3,4- dihydropyrimidinones was achieved in good to excelent yields.

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El objetivo es proponer un procedimiento y un dispositivo que permitan la extracción de un fertilizante contenido en una envoltura hidrosoluble sin generar residuos provenientes del envase vacío, evitando el contacto con el producto, garantizando la extracción del fertilizante mediante la disolución previa del envoltorio y a una circulación de agua a su través, incorporando un sistema de filtrado final, y facilitando el llenado y limpieza del dispositivo mediante un sistema de apertura y cierre roscado.

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The vineyard culture, in the Southwest of Paraná, has faced an evolution in recently years. However, some technical barriers has contained the expression of its full potential. Among which, the lack of scientific and technical support about the fertilization management and the fertility maintenance of production fields, is the most worrying. This fact, allied with the raising on the consumers demand for ecological correct products, are the motivations for the present study, whose main objective was to evaluate the effects of different fertilizer formulations, based on alternative nutrient sources, on grapevine yield and grape fruit quality, aiming at the improvement of those parameters and the maintenance of soil fertility. To achieve this goal, an experiment has been evaluated since 2008, at the experimental area of the Federal Technological University of Paraná, Campus Pato Branco, where ten treatments were being tested, combining or isolating shale derivates from other alternative nutrient sources. Those are the treatments: T1: Gafsa Rock Phosphate (GRP) + K2SO4; T2: GRP + RPB (Rock Powder Bioland®); T3: GRP + K2SO4 + LH (Laying Hen Litter); T4: GRP+ RPB + LH; T5: GRP + K2SO4 + MBR (Matrix Shale 3); T6: GRP + RPB + MBR; T7: GRP + K2SO4 + MBR + LH; T8: GRP + RPB + LH + MBR; T9: TSP (Triple Superphosphate) + Urea + KCl and T10: absolute control. The usage of fertilization, specially the alternative fertilization, improved soil fertility characteristics and also the yield on the last two evaluated harvests. The potassium sulfate improved the potassium availability on soil, while improved yield on the last three harvests. The MBR improved the phosphorus availability, improved post-harvest conservation and improved the yield on the last evaluated harvest.

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Se presenta una propuesta de pre - factibilidad para el establecimiento de una granja porcina semi tecnificada en la comunidad Wanawas , R io Blanco para la producción de cerdos híbridos. L a granja operara con 20 hembras reproductoras acriolladas y dos verracos de raza pura para la obtención de de cerdos di híbridos para reproductores y trihibrido para engorde. El objetivo de la granja además del abastecimiento de cerdos, es promover la crianza de animales de mayor valor genético. Uno de los ejes de la granja es la produc ción de l a s materias primas ( maíz, yuca, malanga y otros productos ) necesaria s para la alimentación de los cerdos. El anális is del mercado en la zona determino, que la granja operara en una zona donde la oferta de cerdos es baja y la demanda es alta lo que asegura la venta total de los animales, se ofertara a los productores cerdaza como fertilizante lo que ayudara a disminuir el impacto que tiene el uso agroquímicos en los suelos de la zona. El plan de inversiones supone la construcción de tres galeras para el manejo de los animales así como de dos pilas para el tratamiento de agua para su posterior utilización como agua de ri ego y la captación de las excretas las cuales serán aprovech adas para la obtención de Cerdaz a y su venta como abono orgánico. .El análisis financiero demostró que la propuesta es factible de implementación debido a que logra una rentabilidad del 49.54 % con una rel ación beneficio costo de C$ 1.59 . Se comprobó que tan sensible es la propuesta obteniendo que la mism a soporte una disminución del 19 % en los ingresos lo que genera una relación beneficio costo de 1.29 , en cambio al incrementarse los costos de prod ucción (40%) se obtiene una relación beneficio costo de 1.4 9. Por lo anterior se puede afirmar que la propuesta es viable en los términos en que la misma fue formulada.

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Se presenta un estudio de pre - factibilidad para el funcionamiento de una granja avícola de gallinas ponedoras en el municipio de San Sebastián de Yalí para la producción de huevos de consumo en un sistema de manejo semi - tecnificado . En la propuesta se contempla que la granja operara con una base de 3,000 aves . Uno de los objetivos de la granja además del abastecimiento de huevos , es pro mover el consumo de huevo de gallina en la dieta cotidiana de la población de San Sebastián de Yalí . El análisis del mercado realizado en la zona determino, que la granja operara en una zona donde la oferta de huevos es baja y la demanda es alta lo que asegura la venta total de los huevos p roducidos tanto en el municipio , a su vez se ofertara a los productores de la zona gallinaza como fertilizante o para la alimentación animal lo que ayudara a disminuir el impacto que tiene el uso agroquímicos en los su elos de la zona y a mejorar la alimentación de los animales . El plan de inversiones supone la construcción de una galera equipada para el manejo de l as aves . .El análisis financiero demostró que la propuesta es factible de implementación debido a que logra una rentabilidad del 50.23 % con una rel ación beneficio costo de C$ 1.20 . Se comprobó que tan sensible es la propuesta obteniendo que la mism a soporte una disminución del 19 % en los ingresos lo que genera una relación beneficio costo de 1.10 , en cambio al incrementa rse los costos de producción (11.5 %) se obtiene una relación beneficio costo de 1.08 . Por lo anterior se puede afirmar que la propuesta es viable en los términos en que la misma fue formulada.

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El trabajo de investigación fue realizado en el centro de experimentación y validación de tecnología (CEVAT), Las Mercedes ubicado en el km 11 carretera norte, entrada al CARNIC 800 metros al norte, con coordenadas geográficas 12°10’14” a 12°08’05” de latitud Norte y 86°10’22” a 86°09’44” longitud Oeste a 56 msnm, durante los meses de octubre 2015 a enero 2016. Los suelos de esta zona son derivados de cenizas volcánicas, suelos jóvenes y pertenece a la serie Las Mercedes, con textura franco arcillosa. El objetivo es comparar el efecto que tiene las diferentes fuentes de fertilizantes sintéticos y orgánicos sobre el crecimiento y rendimiento del cultivo de maíz, el primero con fertilizante tradicional (12-30-10 y urea), el segundo con fertilizantes especial (fertimaiz y nitro xtend) y el orgánico (humus de lombriz). Se estableció un arreglo unifactorial en diseño de bloques completo al azar con cuatro repeticiones y tres tratamientos. Los datos fueron analizados con el programa INFOSTAT. La dimensión total del ensayo fue de 410.8 m2. El análisis de los resultados muestra que hubo diferencia significativa en la variable: diámetro del tallo (2.15 cm), largo de la hoja (98.89 cm), altura de inserción de la panoja (225.08 cm), presentando el tratamiento tradicional los mejores resultados, las variables, altura de la planta (215.43 m), numero de hojas (8.58), ancho de la hoja (8.78 cm), área foliar (604.06 cm2). Inserción de la espiga (129.77 cm), longitud de la mazorca (15.03 cm), numero de hileras (14.58), rendimiento (3453.48 kg ha-1) refleja los mejores resultados al fertilizar con el tratamiento especial. La fertilización orgánica no presentó buenos resultados en las variables de crecimiento y rendimiento en el cultivo de maíz generando pérdida económica en el primer ciclo de fertilización orgánica.

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Dissertação submetida à Universidade de Lisboa, Faculdade de Ciências para a obtenção do Grau de Mestre em Microbiologia Aplicada.