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| Registros recuperados: 113 | |
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| Loureiro, Sofia; Jauzein, Cecile; Garces, Esther; Collos, Yves; Camp, Jordi; Vaque, Dolors. |
| The influence of organic nutrients on the evolution of Pseudo-nitzschia delicatissima cultures was investigated in an enrichment experiment with high-molecular-weight dissolved organic matter (HMWDOM) and in an uptake assay with N-15-ammonium and N-15-urea. HMWDOM was extracted from seawater collected at a nearby shore station during the decline of a diatom bloom. Four incubations were prepared: L1/5+DOM (P. delicatissima grown in L1 growth medium with 1/5 of the nitrate concentration of standard L1), (L1-N)+DOM (L1 without nitrate, i.e. nitrogen-deficient treatment), L1-DOM (control culture without added DOM) and BV+DOM (bacterial and viral control, free of microalgae). Incubations were carried out for 10 days. Chlorophyll a concentrations differed after... |
| Tipo: Text |
Palavras-chave: Harmful Algal Blooms (HABs); Nitrogen Uptake; Urea; Dissolved Organic Matter (DOM). |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6438.pdf |
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| Pedreira,B.C.; Barbosa,P.L.; Pereira,L.E.T.; Mombach,M.A.; Domiciano,L.F.; Pereira,D.H.; Ferreira,A.. |
| ABSTRACT The objective of this study is to verify the population density and the dynamics of tillering in the Marandu palisade grass sward subjected to nitrogen (N) fertilization strategies, characterized by the N supply via urea or bacterial inoculant (Azospirillum brasilense). The treatments comprised of four nitrogen fertilization strategies: (A) Without fertilization, (B) 80 kg N/ha, (C) inoculant (A. brasilense), and (D) 80 kg N/ha + inoculant, distributed in a randomized complete block design, with three replications. The nitrogen supply strategies were evaluated during six periods: October, November, and December (2012) as well as January, March, and April (2013). The nitrogen dose or inoculant had no effect on the tiller appearance rate (TAR),... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Diazotrophic bacteria; Nitrogen biological fixation (NBF); Stability index; Tillers; Urea. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352017000401039 |
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| Teixeira, Fábio Andrade; Universidade Estadual do Sudoeste da Bahia; Bonomo, Paulo; Universidade Estadual do Sudoeste da Bahia; Pires, Aureliano José Vieira; Universidade Estadual do Sudoeste da Bahia; Silva, Fabiano Ferreira; Universidade Estadual do Sudoeste da Bahia; Abreu Filho, George; Universidade Estadual do Sudoeste da Bahia; Viana, Pablo Teixeira; Universidade Estadual do Sudoeste da Bahia. |
| The objective of this work was to evaluate the tiller population density in Urochroa decumbens pasture deferred for 95 and 140 days, aiming to determine the best strategy for nitrogen fertilization. Four fertilization strategies at the beginning and end of summer (0-0, 100-0, 50-50, 0-100 kg ha-1 of N) were studied, respectively, with four repetitions. For the pastures deferred for 95 days, the population densities of vegetative tillers were greater (p < 0.05) for the strategy 0-100. At the end of the deferment period, the weight of the vegetative tillers per hectare was greater for the strategy 0-100, followed by the strategy 50-50. The densities of vegetative tillers, evaluated in the pastures deferred for 140 days, were greater (p < 0.05)... |
| Tipo: Pesquisa de campo |
Palavras-chave: Density; Deferment; Grazing; Tiller; Urea. |
| Ano: 2013 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/10243 |
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| García-portela, Maria; Reguera, Beatriz; Gago, Jesus; Le Gac, Mickael; Rodríguez, Francisco. |
| Dinoflagellate species of Dinophysis are obligate mixotrophs that require light, nutrients, and prey for sustained growth. Information about their nitrogenous nutrient preferences and their uptake kinetics are scarce. This study aimed to determine the preferred nitrogen sources in cultures of D. acuminata and D. acuta strains from the Galician Rías Baixas (NW Spain) and to compare their uptake kinetics. Well-fed versus starved cultures of D. acuminata and D. acuta were supplied with N15 labeled inorganic (nitrate, ammonium) and organic (urea) nutrients. Both species showed a preference for ammonium and urea whereas uptake of nitrate was negligible. Uptake rates by well-fed cells of D. acuminata and D. acuta were 200% and 50% higher, respectively, than by... |
| Tipo: Text |
Palavras-chave: Dinophysis; Nitrate; Ammonium; Urea; Uptake rates; N-15 incubations; Antibiotic treatment. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00606/71770/70250.pdf |
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| Araujo, Hellen Patricia de Oliveira; Paula, Nelcino Francisco de; Martello, Hariany Ferreira; Teobaldo, Ronyatta Weich; Pereira, Luana Barros; Mora, Lays Martins; Valentim, Jean Kaique; Antunes, Hellen Cristina Ferreira. |
| This work was carried out to evaluate the inclusion of urea and tannin in multiple supplements on ingestive behavior of cattle in pasture. The experiment was taken in the Cattle Nutrition pasture of the Experimental Farm of the Federal University of Mato Grosso, in 4 x 4 Latin square design with a factorial arrangement 2 x 2 (with and without urea and with and without tannin). Four Nellore bulls were used, with average weight of 470 kg and an average age of 20 months, randomly divided in: Supplement without urea and without tannin, Supplement without urea and with tannin, supplement with urea and without tannin, and supplement with urea and with tannin. The level of supplementation used was 1% of body weight during the dry period of the year. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Natural additives; Forage; Supplementation; Urea; Tannins. |
| Ano: 2020 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAnimSci/article/view/47607 |
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| GOMES,MATEUS P.; ZONTA,EVERALDO; STAFANATO,JULIANO B.; PEREIRA,ARIANA M.. |
| Abstract The objective of this study was to evaluate NBPT, zeolite and humic acid in different concentrations as inhibitors of the activity of the enzyme urease. The activity of the urease enzyme was quantified by the methods proposed by May and Douglas (1976) and Witte and Medina-Escobar (2001). For this reason, two experiments were conducted in a completely randomized design in split plots, in which the incubation periods are the plots and the fertilizers with the inhibitors at the different concentrations are the subplots with three replications. Fifteen fertilizers based on NBPT-coated urea, humic acid and zeolite were used in different concentrations. The two methods of analysis used in the experiment confirmed the efficiency of NBPT in inhibiting the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Humic acid; Nbpt; Zeolite; Urea. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000703685 |
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| Cartes,Paula; Jara,Alejandra A; Demanet,Rolando; Mora,María de la Luz. |
| Incubation studies were carried out to evaluate the effect of temperature and urea supply level on both the urease activity and the kinetics of N mineralization in two Andisols of Southern Chile. Our results showed that urease activity was higher in Piedras Negras soil (PNS) than Freiré soil (FS) at 24 and 48 h, and the enzyme was activated when the temperature increased from 5 to 21 °C. Urease activity followed a simple Michaelis-Menten kinetics. In PNS, the Michaelis Menten constant (Km) decreased, whereas the maximum enzyme reaction velocity (Vmax) and the catalytic efficiency increased when the temperature was raised up to 21 °C at 24 and 48 h of soil incubation. In FS, urease activity was the highest at 24 h, and it decreased at 48 h as a consequence... |
| Tipo: Journal article |
Palavras-chave: Urease activity; N mineralization; Urea; Andisols. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912009000100006 |
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| Oliveira,Tadeu Silva de; Leonel,Fernando de Paula; Pereira,José Carlos; Silva,Cássio José da; Baffa,Danielle Ferreira; Zervoudakis,Joanis Tilemahos. |
| The objective of this study was to evaluate the effect of five nitrogen doses on the productive and quality characteristics and the use efficiency of Brachiaria brizanthacv. Marandu grass. The treatments consisted of four doses of nitrogen (0, 60, 120, 180 and 240 kg ha-1), distributed through a completely randomized design with four replicates. Samples of the material were collected to analyze productivity variables, concentrations of neutral detergent fiber, crude protein and neutral detergent insoluble nitrogen, and in vitro dry matter digestibility. The nitrogen use efficiency, recovery of the applied nitrogen (RAN) and agronomic efficiency of the applied nitrogen (AE) were calculated. Dry mass production increased by 1,624.67 (kg/ha) as the nitrogen... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen use efficiency; Nutritional characteristics; Urea. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982014000800440 |
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| Registros recuperados: 113 | |
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