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| Registros recuperados: 113 | |
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| Tulli, F; Vachot, Christianne; Tibaldi, E; Fournier, Vincent; Kaushik, Sadasivam. |
| The role of dietary arginine in affecting nitrogen utilisation and excretion was studied in juvenile European sea bass (Dicentrarchus labrax) fed for 72 days with diets differing in protein sources (plant protein-based (PM) and fish-meal-based (FM)). Fish growth performance and nitrogen utilisation revealed that dietary Arg surplus was beneficial only in PM diets. Dietary Arg level significantly affected postprandial plasma urea concentrations. Hepatic arginase activity increased (P < 0.05) in response to dietary Arg surplus in fish fed plant protein diets; conversely ornithine transcarbamylase activity was very low and inversely related to arginine intake. No hepatic carbamoyl phosphate synthetase III activity was detected. Dietary arginine levels did... |
| Tipo: Text |
Palavras-chave: Dicentrarchus labrax; Sea bass; Excretion; Arginase; Urea; Arginine. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6317.pdf |
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| Jauzein, Cecile; Collos, Yves; Garces, E; Vila, M; Maso, M. |
| In batch cultures of four Mediterranean strains (from France, Italy, and Spain) of Alexandrium catenella (Whedon et Kof.) Balech growing on a daily light cycle, ammonium and urea uptake were estimated by the N-15 tracer technique. Ammonium uptake could be described by Michaelis-Menten kinetics along a substrate gradient of 0.1-10 mu gat N.L-1 for the four strains, while two different patterns were observed for urea uptake with Michaelis-Menten kinetics for one strain and linear kinetics for the others. In all cases, an increase in uptake rates with time was noted over the daylight period. This trend led to a net increase in the maximum uptake rate (V-max; for saturable kinetics) and in the initial slope alpha. For ammonium, V-max increased by a factor of... |
| Tipo: Text |
Palavras-chave: Urea; Uptake kinetics; Temporal variability; Ammonium release; Ammonium; Alexandrium catenella. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6416.pdf |
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| Goeyens, L.; Kindermans, N.; Yusuf, M.A.; Elskens, M.. |
| Several earlier studies underpin the important role of dissolved organic matter and more particularly urea in phytoplanktonic nitrogen uptake fluxes. Generally, the determination of urea concentrations relies on the formation of an imidazolone-thiosemicarbizide complex, a complexation which requires very accurate temperature control when carried out at high temperature. It is also possible, however, to obtain reliable results with a room temperature procedure. The measured abundances for both complexation at high temperature (85 degree C, 20 min) and at ambient temperature (22 degree C, 72 h) are closely comparable. Lower values are observed for temperatures <10 degree C though. Moreover, a comparison of both techniques reveals similar precision... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dissolved organic carbon; Sea water; Temperature; Urea; Water analysis. |
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7858 |
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| Silva,Edson Cabral da; Muraoka,Takashi; Franzini,Vinícius Ide; Villanueva,Felipe Carlos Alvarez; Buzetti,Salatiér; Moreti,Dolorice. |
| The objective of this work was to evaluate the utilization by corn plants of P from triple superphosphate fertilizer labeled with 32P (32P‑TSP), and of P from soil as affected by N rates and by the green manures (GM) sunn hemp (Crotalaria juncea) and millet (Pennisetum glaucum). The experiment was carried out using pots filled with 5 kg Oxisol (Rhodic Hapludox). A completely randomized design was used, in a 4x4x2 factorial arrangement, with four replicates. The treatments were: four P rates as TSP (0, 0.175, 0.350, and 0.700 g P per pot); four N rates as urea (0, 0.75, 1.50, and 2.25 g N per pot); and sunn hemp or millet as green manure. The additions of N and P by the GM were taken into account. After grain physiologic maturation, corn dry matter, P... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Cover crop; Isotopic dilution; Oxisol; Radioisotope; Urea. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2012000800016 |
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| Guimarães,Clóvis Ribeiro; Azevedo,Rafael Alves de; Campos,Mariana Magalhães; Machado,Fernanda Samarini; Pedroso,Alexandre Mendonça; Carvalheira,Luciano de Rezende; Tomich,Thierry Ribeiro; Pereira,Luiz Gustavo Ribeiro; Coelho,Sandra Gesteira. |
| Abstract: The objective of this work was to evaluate the effect of reducing crude protein (CP) contents in diets with a constant metabolizable protein content on the intake, performance, nitrogen balance, and nutrient digestibility of lactating Holstein-Gyr cows. Animals (n = 24, 103±23 days in milk) were allocated to four treatments (n = 6 per group) with different CP contents: 127, 132, 139, and 156 g kg-1 dry matter (DM). DM intake was not affected by treatments. CP intake and digestibility increased linearly with higher CP contents. Milk yield (23.7±3 kg per day) and the percentages of milk protein (3.3±0.2%) and fat (3.8±0.5%) were not affected by CP reduction. Milk and blood urea nitrogen increased linearly with the increase of CP in the diet,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen; Protected soybean meal; Soypass; Urea. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000700858 |
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| Rech,Cleber; Albuquerque,Jackson Adriano; Corrêa,Juliano Corulli; Mafra,Alvaro Luiz; Bortolini,Diego. |
| Abstract: The objective of this work was to evaluate the superficial and injected applications of swine slurry and urea to the soil, regarding their effects on the physical properties of a Nitossolo Vermelho distroférrico under a no-tillage system. The treatments were: injected slurry into the groove with a liquid swine slurry injector (LSSI); slurry on surface, applied on the lines by the LSSI kept raised; urea injected by opening the groove with the LSSI and distributed manually; and corn, under no-tillage, as a control. Sowing and the injection of liquid slurry or urea do not modify the organic carbon content, pH, and aggregation, but alter the soil bulk density and porosity in the mobilized line, and increase the macropores. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Porosity; Soil structure; Urea. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2018000400518 |
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| López-Elías,JA; González-Vega,R; Márquez-Ríos,E; Torres-Arreola,W. |
| Las proteínas son uno de los principales metabolitos que componen la biomasa de las microalgas que constituyen la dieta de los organismos marinos cultivados en acuacultura, ya que son imprescindibles para su crecimiento. La cantidad producida de este componente es influenciada por los nutrimentos, temperatura e intensidad luminosa, entre otros factores. En la presente investigación se evaluó el crecimiento, producción de biomasa, proteínas y patrón electroforético de las proteínas de Chaetoceros muelleri, cultivadas con dos fuentes de nitrógeno (nitratos y urea) a tres concentraciones, utilizando el medio f/2 (0,88 moles/L) (nitratos) como control. Los tratamientos fueron los medios 2f (3,53 moles/L) y 4f (7,05 moles/L) con NO3 -, y los medios f/2 (0,88... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chaetoceros muelleri; Biomasa; Proteínas; Urea; Nitratos. |
| Ano: 2015 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1851-56572015000200010 |
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| Fontoura,Sandra Mara Vieira; Viero,Fernando; Moraes,Renato Paulo de; Bayer,Cimélio. |
| ABSTRACT High winter cereal yields depend on an adequate supply of nitrogen (N). We developed a system for indicating N rates for wheat and barley in the South-Central region of the state of Paraná, Brazil, using results of 72 field experiments conducted from 2007 to 2012. The N rates recommended for winter cereals were estimated to supply the amounts of N fertilizer needed to obtain increasing yields (<3.5, 3.5-4.5, 4.5-5.5, and >5.5 Mg ha-1) of crops grown after soybean and corn on soils with a variable organic matter content (<40, 40-60, and >60 g dm-3). The apparent mineralization rate of soil N was estimated to be 1 % and the N fertilization efficiency 50 %. The N rates recommended for wheat ranged from 30 to 150 kg ha-1 when cultivated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum; Hordeum vulgare L.; N indication; Urea. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832017000100533 |
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| Fontoura,Sandra Mara Vieira; Bayer,Cimélio. |
| Ammonia (NH3) volatilization can reduce the efficiency of urea applied to the surface of no-till (NT) soils. Thus, the objectives of this study were to evaluate the magnitude of NH3 losses from surface-applied urea and to determine if this loss justifies the urea incorporation in soil or its substitution for other N sources under the subtropical climatic conditions of South-Central region of Paraná State, Brazil. The experiment, performed over four harvesting seasons in a clayey Hapludox followed a randomized block design with four replicates. A single dose of N (150 kg ha-1) to V5 growth stage of corn cultivated under NT system was applied and seven treatments were evaluated, including surface-applied urea, ammonium sulfate, ammonium nitrate, urea with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen fertilizer; Urea; Corn; Urease. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000500020 |
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| Oliveira,Thomas Carlos; Fontes,Renildes Lúcio Ferreira; Rezende,Sebastião Tavares de; Víctor Hugo,Alvarez V.. |
| Nickel is a micronutrient involved in nitrogen metabolism and a constituent of the urease molecule. Plant growth and urease activity were evaluated in lettuce (Lactuca sativa L.) grown in soil-filled pots in a 2 x 8 factorial design with two nitrogen (N) sources and eight Ni rates, with five replications. Nitrogen was applied at 200 mg dm-3 (half the dose incorporated into the soil at seedling transplanting and half top-dressed later) using the sources NH4NO3 (AN) and CO(NH2)2 (Ur). The Ni treatments (0, 2, 4, 8, 12, 16, 24 and 32 mg dm-3) were applied as NiCl2. The shoot dry-matter yield, leaf urease activity, Ni levels in the lettuce leaves and Ni levels extracted from soil with Mehlich-3 (M-3) and DTPA were determined. In the plants supplied with AN,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonium nitrate; Urea; Plant nutrition; Lactuca sativa L. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000300016 |
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| Teixeira Filho,Marcelo Carvalho Minhoto; Buzetti,Salatiér; Andreotti,Marcelo; Sá,Marco Eustáquio de; Arf,Orivaldo; Megda,Márcio Mohamed. |
| High wheat yields require good N fertilization management. The objective of this study was to evaluate the effects of different N applications at sowing using Entec (N source with nitrification inhibitor) and urea (traditional N source) at covering, on four wheat cultivars. The experiment was conducted in a randomized block design in a factorial scheme, with four replications, at the Experimental Station of the Faculdade de Engenharia de Ilha Solteira - UNESP, on a dystrophic, epi-eutrophic alic Red Latosol with loamy texture, formerly under savannah vegetation. Four N rates (0, 60, 120, and 180 kg ha-1) were tested, applied at sowing in the case of Entec and top-dressed 40 days after plant emergence in the case of urea, and the four wheat cultivars E 21,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum L.; Savannah soil; Entec; Urea; Grain yield; Yield components. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500023 |
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| Souza,José A.; Rocha,Genelício C.; Gomes,Mateus de P.; Rezende,Carlos H. S.. |
| ABSTRACT The objective of this study was to evaluate nitrogen losses by NH3 volatilization and quantify the upward and downward NO3- flows in Latosol cultivated with arabica coffee. An experiment was set in 2010, in Viçosa-MG, Brazil (20º 41’ S and 42º 48’ W), in a randomized block design in a (3 x 2) + 1 factorial arrangement with three nitrogen doses (200, 400 and 600 kg ha-1), two forms of urea (conventional and NBPT urease inhibitor-treated) and one additional treatment without nitrogen fertilization, with four replicates. Semi-open type chambers were installed to quantify NH3 volatilization. To determine the concentration and flow of NO3- a soil solution extractor was installed in each plot at a 1-m depth together with three tensiometers at depths of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: NBPT; Urea; Nitrate flow. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000600390 |
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| Silva,Raphael R.; Zucareli,Claudemir; Fonseca,Inês C. de B.; Riede,Carlos R.; Gazola,Diego. |
| ABSTRACT The aim of this study was to evaluate the influence of nitrogen (N) fertilization, environment and cultivars on the protein concentration, sodium dodecyl sulfate sedimentation test (SDSS) volume and falling number in wheat. The experimental design was a randomized blocks in split plot scheme with four repetions. Four wheat genotypes were evaluated under six N managements in four enviroment (subplots). The wheat genotypes evaluated were IPR Catuara TM, BRS Gaivota, Quartzo and CD 120. Protein concentration, SDS sedimentation test, falling number and grain yield were evaluated. Combined analysis of variance for the four environment was performed and means were compared by Tukey test at p ≤ 0.05. The environmental effect is greater than the genotype... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum L.; Grain yield; Urea; Ammonium sulfate. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662019001100826 |
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| Costa,Juliane S. P.; Mantai,Rubia D.; Silva,José A. G. da; Scremin,Osmar B.; Arenhardt,Emilio G.; Lima,Andressa R. C. de. |
| ABSTRACT Single or split nitrogen (N) supply can maximize the expression of wheat yield indicators. The objective of the study was to evaluate the greater N use efficiency on wheat yield indicators by the single and split N supply under favorable and unfavorable year conditions to the crop in succession system of high and reduced residual N release. The study was conducted in 2014 and 2015, in a randomized complete block design with four replicates in a 4 x 3 factorial, for N-fertilizer doses (0, 30, 60, 120 kg ha-1) and supply forms [full dose (100%) in the phenological stage V3 (third expanded leaf); split dose (70 and 30%) in the phenological stages V3/V6 (third and sixth expanded leaves, respectively) and; split dose (70 and 30%) in the phenological... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum; Urea; Residual N; Temperature; Rainfall. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000100016 |
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| Kaefer,João E.; Richart,Alfredo; Nozaki,Márcia de H.; Daga,Jacir; Campagnolo,Rodrigo; Follmann,Paulo E.. |
| ABSTRACTThe aim of this study was to evaluate the response of the canola crop to nitrogen (N) sources and split application. The experiment was carried out in two agricultural years (2009 and 2010), at the experimental unit of the Pontifical Catholic University of Paraná - PUCPR, Campus of Toledo. A completely randomized design in 5 x 2 factorial scheme was adopted in the experiment. The treatments consisted of five split applications of N at sowing and/or as top dressing (0 and 0, 120 and 0, 0 and 120, 40 and 80, 80 and 40 kg of N ha-1) and two N sources (ammonium sulfate and urea), with four replicates. The canola genotype Hyola 61 was used in the experiment, which was evaluated for plant height, number of plants m-2, shoot dry matter, leaf area, mass of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urea; Ammonium sulfate; Protein content; Oil content; Brassica napus L.. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662015001101042 |
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| Tosta,Mauro da S.; Almeida,João P. N. de; Góes,Glêidson B. de; Freire,Priscilla de A.; Mendonça,Vander. |
| ABSTRACT ‘Pitombeira’ does not have organized cultivation, thus requiring information related to the production of seedlings, particularly in relation to chemical fertilizer. In this context, an experiment was conducted in order to define the best dose of nitrogen (N), using urea as N source, to be applied in ‘pitombeira’ seedlings. The experimental design was complete randomized blocks with four replicates and ten plants per plot, testing five N doses (0, 400, 800, 1.600 and 3.200 mg dm-3). Data were submitted to analysis of variance and regression. The non-destructive measurements (number of leaves, stem diameter, shoot length and the ratio between shoot length and stem diameter) were evaluated at 30, 60, 90 and 120 days after transplanting (DAT). In... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: ‘pitombeira’; Propagation; Urea. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000700443 |
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| Salomão,Luiz Carlos Chamhum; Siqueira,Dalmo Lopes de; Silva,Danielle Fabíola Pereira da. |
| Abstract The rejuvenation pruning or plant prune is a practice used in fruits species such mango tree, whose plants can exceed ten meters heigh, compromising the implementation of practices such as spraying and harvesting. This study aimed to evaluate the resumption of production of adult ‘Ubá’ mango trees, previously pruned and subjected to fertilization with increasing levels of nitrogen over five seasons. The experiment was conducted in Visconde do Rio Branco, MG. Nineteen years old mango trees were pruned and reduced to the primary branches, about 1.5 m above the ground. Excess shoots were removed, remaining five to six branches per tree. In the year in which the plants were pruned, the nitrogen fertilization was initiated with different doses,... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Mangifera indica L.; Urea; Mineral nutrition. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452018000203002 |
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| Registros recuperados: 113 | |
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