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| Registros recuperados: 113 | |
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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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| Antonelli,A.C.; Torres,G.A.S.; Soares,P.C.; Mori,C.S.; Sucupira,M.C.A.; Ortolani,E.L.. |
| Twelve steers were intraruminally administered a high dose (0.5g/kg BW) of urea to study the damage effect of ammonia poisoning on liver and/or muscles. Blood samples were collected to determine ammonia and activities of gammaGT, AST and CK. Eleven steers were successfully poisoned and treated properly, but one succumbed. Poisoned cattle showed high concentration of ammonia, and higher activities of AST and CK. The higher the ammonia, the greater were the activities of AST (r=0.59) and CK (r=0.61). The correlation between AST and CK was high and significant (r=0.80), but not between AST and gammaGT (r=0.19). The activities of AST and CK were higher after the beginning of the convulsive episodes due to ammonia poisoning. Those results showed that occurred... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cattle; Ammonia poisoning; Urea; Muscle damage; Liver. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352007000100002 |
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| Otto,Rafael; Zavaschi,Eduardo; Souza Netto,Gerson José Marquesi de; Machado,Bianca de Almeida; Mira,Acácio Bezerra de. |
| ABSTRACT Maintenance of crop residues over soil surface under conservational systems limits incorporation of nitrogen fertilizers into the soil. Application of urea over crop residues enhance N-NH3 volatilization losses, justifying the usage of urease inhibitors or N sources less susceptible to volatilization under such conditions. This study aimed to evaluate volatilization losses from N sources applied over sugarcane straw. A field trial was carried out in a sugarcane field in Iracemapolis, Sao Paulo on a Typic Kandiudox in June 2014. We used a complete block experimental design, with seven treatments and four replications. Treatments included Control [CO], ammonium nitrate [AN], NS30TM (ammonium nitrate-75% and ammonium sulfate-25% fused mixture)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urea; NBPT; NS 30 TM; Green cane. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902017000300413 |
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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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| Brunetto,Gustavo; Ceretta,Carlos Alberto; Melo,George Wellington Bastos de; Girotto,Eduardo; Ferreira,Paulo Ademar Avelar. |
| This study was carried out to evaluate the yield, total N content in leaves and must composition of grapes from the Cabernet Sauvignon variety subjected to the application of urea and organic compost. Cabernet Sauvignon grapevines in Rosário do Sul, RS, Brazil, in 2008, 2009 and 2010 were subjected to annual application of 40 kg N ha-1 in the form of organic compost and urea, and compared to unfertilized grapevines. In the 2008/09, 2009/10 and 2010/11 crop seasons, leaves were collected for analysis of total N content. At maturation of the grapes, the yield and quality attributes of the must were evaluated. The application of N sources, especially organic compost, increased the N content in the whole leaf at full flowering. Application of organic compost... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Urea; Organic compost; Leaf analysis; Must quality; Vitis vinifera. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452013000400015 |
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| Buso,W.H.D.; França,A.F.S.; Miyagi,E.S.. |
| The bromatological composition and in vitro dry matter digestibility of millet cultivars were assessed for different nitrogen doses and two sowing seasons in the Ceres municipality of Goiás state, Brazil. The treatments consisted of three millet cultivars (ADR-7010, ADR-500 and BRS-1501), four nitrogen (N) doses (0, 50, 100 and 200kg ha-1 of N) and two sowing seasons. Three replicates and a randomised block design with a 3 x 4 x 2 factorial scheme were used. Two cuttings were performed in each season when plants reached an average height of 0.70 cm. No significant interactions were observed between or among cultivars for N doses and dry matter (DM), crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents. The DM, CP, NDF... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Fibres; Forage; Dry matter; Pennisetum glaucum; Protein; Urea. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352014000300887 |
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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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| Teixeira, Fábio Andrade; UESB; Bonomo, Paulo; UESB; Pires, Aureliano José Vieira; UESB; Silva, Fabiano Ferreira; UESB; Martins, Giselle Caroline Fernandes; UESB; Cardoso, Elisângela Oliveira; UESB. |
| O objetivo deste trabalho foi avaliar as características estruturais de pastos de Brachiaria decumbens diferidos por 140 dias, visando determinar a estratégia mais adequada de adubação nitrogenada. Foram estudadas quatro estratégias de adubação no início e no final do verão (0-0, 100-0, 50-50, 0-100 kg ha-1 de N), respectivamente, com quatro repetições. Para avaliação das densidades volumétricas, a forragem foi colhida em três estratos: estrato A- acima de 40 cm; B- 20-40 cm; e C- 0-20 cm do solo. O índice de tombamento foi menor (p < 0,05) para a estratégia de adubação com 100 kg ha-1 de N aplicados no final do verão. No estrato B foram observadas maiores (p < 0,05) densidades de forragem total, de lâmina foliar e de colmo verde para estratégia de... |
| Tipo: Pesquisa de campo |
Palavras-chave: Forragicultura e pastagens acamamento; Densidade; Diferimento; Pastagem; Perfilho; Ureia falling; Density; Deferment; Grazing; Tiller; Urea. |
| Ano: 2011 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/10212 |
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| Casanova P,Manuel; Benavides Z,Carlos. |
| Empleando información cartográfica y una base de datos se predijo la distribución espacial de la volatilización a partir de urea granular aplicada superficialmente en la zona central de Chile, bajo el supuesto que el potencial de pérdida amoniacal sólo depende de las propiedades del suelo, y que se asocian al espacio físico conocido como micrositio. Las propiedades relevantes (capacidad de intercambio catiónico, actividad ureásica, tamponamiento del pH y pH del suelo post-hidrólisis de la urea o pH/) para el proceso de pérdida de amoníaco, se definieron acorde a un modelo conceptual, determinándose que los valores umbrales para un alto potencial de pérdidas son: CIC ≤ 20 cmol(+) kg-1, actividad ureásica ≥ 40 N-urea g-1 h-1 and pH... |
| Tipo: Journal article |
Palavras-chave: Funciones de pedotransferencia; Urea; Volatilización. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000100002 |
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| Goes, Rafael Henrique de Tonissi e Buschinelli de; Universidade Federal da Grande Dourados; Miyagi, Eliane Sayuri; Universidade Federal da Grande Dourados; Oliveira, Euclides Reuter de; Universidade Federal da Grande Dourados; Brabes, Kelly Cristina da Silva; Universidade Federal da Grande Dourados; Patussi, Rosielen Augusto; Universidade Federal da Grande Dourados; Dambrós, Carlos Eduardo; Universidade Federal da Grande Dourados. |
| Thirty-six experimental silos arranged in a completely randomized 4 x 3 factorial design were provided to evaluate the chemical changes of sunflower silage treated with soybean hulls, sunflower crushed and urea at 14, 21 and 28 days of ensilage. The additives were based on 5% natural matter, whereas control consisted of silage with 100% sunflower plant. OM, NDIP, and MM had average rates 911.2; 86.6 and 92.9 g kg-1 of dry matter respectively. The addition of soybean hulls and sunflower crushed increased DM rates after 28 and 21 days. Urea increased nitrogen fractions and the addition of soybean hulls increased total carbohydrate content of silage by 5.1%, whereas the addition of sunflower crushed decreased the same by 2.18%. NDF, ADF and hemicellulose... |
| Tipo: Pesquisa |
Palavras-chave: 5.04.03.03-6 sunflower crushed; Lignin; NDF; PH; Soybean hulls; Urea. |
| Ano: 2013 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/14049 |
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| Pires,Aureliano José Vieira; Carvalho,Gleidson Giordano Pinto de; Ribeiro,Leandro Sampaio Oliveira. |
| Chemical treatment of roughage has been the aim of studies for a long time. However, until nowadays, many questions are arisen due to the efficiency of additives used in relation to the variation of answers, either in nutritive value of treated roughage or in performance of animals feed with diet containing such roughage. This revision will approach the main and most used products, which are anhydrous ammonia, urea, sodium hydroxide and calcium oxide. It has been noticed that ammonization (both for anhydrous ammonia and urea) has presented more efficient result in animal's performance when compared with sodium hydroxide or calcium oxide. However, regarding its nutritive value, both sodium hydroxide and calcium oxide have presented a higher efficiency in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonia; Calcium oxide; Sodium hydroxide; Urea. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001300022 |
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| Delbem, Flavia Cristina; Progama de Pós-Graduação em Ciência Animal, Universidade Estadual Paulista, Campus de Araçatuba; Scabora, Márcia Helena; Programa de Pós-Graduação em Produção Vegetal, Universidade Estadual Paulista, Campus de Ilha Solteira; Soares Filho, Cecílio Viega; Universidade Estadual Paulista, Campus de Araçatuba; Heinrichs, Reges; Universidade Estadual Paulista, Campus de Dracena; Ferrari, Tiago Augusto; Progama de Pós-Graduação em Ciência Animal, Universidade Estadual Paulista, Campus de Araçatuba; Cassiolato, Ana Maria Rodrigues; UNESP, Ilha Solteira. |
| The feasibility and increase in the production of new cultivars can be obtained with the practice of nitrogen fertilization. The objective of this study was to verify the effect of sources and levels of nitrogen fertilization, concerning the depths, on the percentage of mycorrhizal colonization and soil fertility when covered by Brachiaria brizantha cv. Xaraés. A randomized blocks design was used and the treatments were under a 3 x 4 factorial scheme, regarding three nitrogen sources (urea, ammonium sulfate, and ajifer-L40) and 4 nitrogen levels (0, 100, 200 and 400 kg ha-1), studied at 2 different depths (0-0.10 and 0.10-0.20 m), with 3 replications. In each plot, the soil samples, composed of 5 simple samples, were collected, sieved, homogenized and sent... |
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Palavras-chave: 5.01.01.04-8 Ajifer; Sulfato de amônio; Ureia; Pastagem Microbiologia e Bioquímica do Solo Ajifer; Ammonium sulfate; Urea; Pasture. |
| Ano: 2010 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/4002 |
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| Coelho,Eugênio F.; Andrade Neto,Torquato M. de; Barros,Damiana L.. |
| The Fertigation is the combined application of water and nutrients to a crop. It can be adapted to all types of agricultural crops. The objective of this study was to evaluate the effect of urea concentration in irrigation water on electrical conductivity of the soil solution and saturation extract along the first cycle of banana cv. Terra Maranhão. The experiment followed a completely randomized design with six treatments and ten replications. Treatments regarded for using three urea concentrations (1.0; 2.5 and 4.0 g L-1) in irrigation water applied by two micro irrigation systems (microsprinkler and drip). Results showed that there was a linear elevation of electrical conductivity of saturation extract and soil solution with the increase on... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Urea; Salinity; Fertirrigation. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000600007 |
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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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| Collos, Y; Vaquer, A; Laabir, M; Abadie, Eric; Laugier, Thierry; Pastoureaud, Annie; Souchu, Philippe. |
| A monitoring program with a weekly sampling frequency over a 15-month period indicates that urea concentrations above a certain threshold level may trigger the blooms of Alexandrium catenella in Thau lagoon. However, urea concentrations were also sometimes related to ammonium and dissolved organic nitrogen concentrations, indicating that the role of urea may not be a direct one. An original approach is used to assess the relative contribution of several nitrogen sources (nitrate, nitrite, ammonium, urea) to growth of A. catenella by comparing nitrogen uptake rates to nitrogen-based growth rates estimated from dilution experiments during four blooms over a 4-year period (2001-2004) in Thau lagoon. Nitrate and nitrite contributed 0.1-14% and 0.1-5%... |
| Tipo: Text |
Palavras-chave: Uptake kinetics; Ammonium; Urea; Growth; Nitrogen; HAB; Alexandrium catenella. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-6454.pdf |
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| Registros recuperados: 113 | |
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