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| Registros recuperados: 425 | |
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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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| Lentz, R.D.; Lehrsch, G.A.; Brown, Bradford; Johnson-Maynard, J.; Leytem, A.B.. |
| Efficient recycling of abundant manure resources from regional dairy industries in the semiarid West requires a better understanding of N availability in manure-amended soils. We measured net N mineralization using buried bags, and crop biomass, N uptake, and yields for sprinkler-irrigated, whole (noneroded) and eroded Portneuf soils (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) subject to a one-time manure application. Treatments included a control, fertilizer, two rates of composted dairy manure (28.4, 64.3 Mg ha–1, dry wt.), and two rates of stockpiled dairy manure (23.3, 45.7 Mg ha–1, dry wt.) applied in the fall before the Year 1 cropping season. Plots were planted to sugarbeet (Beta vulgaris L.), winter wheat (Triticum... |
| Tipo: Article |
Palavras-chave: Manure; Amendments; Nitrogen. |
| Ano: 2011 |
URL: http://eprints.nwisrl.ars.usda.gov/1420/1/1390.pdf |
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| Jauzein, Cecile; Collos, Yves; Laabir, Mohamed; Vaquer, Andre. |
| Uptake rates of three potential N-sources (ammonium, nitrate and N-urea) and two potential C-sources (HCO(3)(-) and C-urea) were estimated during growth of Alexandrium catenella in both light and dark phases. According to the variations observed in (13)C-isotopic ratio, A. catenella cells were not able to use C-urea. Furthermore, decreases in (13)C cell content during darkness revealed a probably high involvement of C recently fixed in dark respiration. Dark N-uptake capacities of A. catenella were characterized by dark/light uptake ratio of 27%, 43% and 65% for NO(3)(-), NH(4)(+) and N-urea, respectively. An accumulation of C-rich compounds during the light period was highlighted through strong diel variations in C:N ratio and would provide C and energy... |
| Tipo: Text |
Palavras-chave: Diel cycle; Dark uptake; Nitrogen; Carbon; Uncoupling; Alexandrium catenella. |
| Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16699/14199.pdf |
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| Tarkalson, D.D.; Kachman, S.D.; Knops, J.M.N.; Thies, J.E.; Wortmann, C.S.. |
| Results of a previous laboratory study indicated that six transgenic crops expressing the Cry1Ab insecticidal protein from Bacillus thuringiensis (Bt) decomposed at a slower rate than their respective non-Bt isolines. Consequently, litter decomposition rates, nitrogen cycling, and carbon pools may change in agricultural systems as the result of the widespread use of Bt crops. In this study, we assessed the decomposition rates and chemical composition of commonly grown hybrids of Bt and non-Bt isolines of corn (Zea mays L.) in the field. Leaves, stalks, and cobs from two Bt corn hybrids (Pioneer 34N44 Bt and NC+ 4990 Bt) and their non-Bt isolines (Pioneer 34N43 and NC+ 4880) were analyzed for biomass fractions (soluble, hemicellulose, cellulose, and lignin)... |
| Tipo: Article |
Palavras-chave: Nitrogen. |
| Ano: 2008 |
URL: http://eprints.nwisrl.ars.usda.gov/1273/1/1250.pdf |
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| Lentz, R.D.. |
| Standard water quality analysis methods recommend that sediment-laden runoff waters sampled to determine dissolved nutrient concentrations be filtered immediately after collection. Few research studies have examined the influence of delayed filtration on sample stability or nutrient loss assessments. Twenty eight runoff water volumes were collected from 3 irrigation furrows during a 12-h irrigation set. Four subsamples of each volume were obtained; 2 were filtered (45 µm) in the field and the other 2 were filtered 10 days later, with or without boric acid treatment (1 mL saturated H3BO3 solution per 100 mL sample). All samples were refrigerated at 4 deg. C. Dissolved reactive P (DRP), NO3-N, and NH4-N concentrations were measured in all filtered... |
| Tipo: Article |
Palavras-chave: Nitrogen; Phosphorous; Nutrients. |
| Ano: 2013 |
URL: http://eprints.nwisrl.ars.usda.gov/1516/1/1480.pdf |
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| DUBOC, E.; GUERRINI, I. A.. |
| RESUMO: A adição de nutrients pode aumentar a chance de sucesso dos plantios de recuperação de áreas degradadas, entretanto, existem poucos estudos sobre os efeitos da fertilização de espécies nativas do Bioma Cerrado. Este trabalho objetivou determinar o efeito sobre o crescimento e a sobrevivência de mudas de aroeirinha, na ausência de nitrogênio e a doses de 10, 20 e 40 kg/ha de N (uréia) e na ausência de fósforo e a doses de 10, 20 e 40 kg/ha de P (superfosfato triplo), plantadas em Latossolo Vermelho-Amarelo, ocupado com pastagem de Brachiaria decumbens. Foi avaliado o diâmetro do colo aos 4, 8 e 12 meses após o plantio e ao final do primeiro ano; o diâmetro de copa, a sobrevivência e a concentração foliar de nutrientes, Al e Na. A sobrevivência não... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Planta nativa; Indigenous organisms; Revegetation; Código Florestal.; Árvore; Aroeira; Cerrado; Fósforo; Nitrogênio; Revegetação.; Nitrogen; Phosphorus; Trees.. |
| Ano: 2007 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/572283 |
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| DUBOC, E.; GUERRINI, I. A.. |
| RESUMO: Apesar das limitações em fertilidade dos solos ácidos do Cerrado, as plantas nativas do bioma possuem diferentes mecanismos de adaptação. O objetivo deste trabalho foi determinar o efeito de doses de nitrogênio (N) e fósforo (P) em mudas de cagaita (Eugenia dysenterica Mart. ex DC.) plantadas em áreas ocupadas com pastagem de Brachiaria decumbens; em um Latossolo Vermelho-Amarelo, onde originalmente havia um Cerrado Denso e em um Plintossolo no entorno de uma Mata de Galeria. Foi avaliada a resposta da cagaita em crescimento e em sobrevivência, na ausência e a doses de 10, 20 e 40 kg ha-1 de N, na forma de uréia e na ausência e a doses de 10, 20 e 40 kg ha-1 de P, na forma de superfosfato triplo, em delineamento experimental de blocos ao acaso. Foi... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Fruta nativa; Indigenous organisms; Revegetation.; Cagaita; Cerrado; Eugenia Dysenterica; Fósforo; Nitrogênio; Revegetação.; Phosphorus.; Nitrogen. |
| Ano: 2007 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/572274 |
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| Tumusiime, Emmanuel; Brorsen, B. Wade; Mosali, Jagadeesh; Johnson, Jim; Locke, James; Biermacher, Jon T.. |
| The parameters of yield response functions can vary by year. Past studies usually assume yield functions are nstochastic ‘‘limited’’ stochastic. In this study, we estimate rye– ryegrass yield functions in which all parameters are random. The three functional forms considered are the linear response plateau, the quadratic, and the Spillman-Mitscherlich. Nonstochastic yield models are rejected in favor of stochastic parameter models. Quadratic functional forms fit the data poorly. Optimal nitrogen application recommendations are calculated for the linear response plateau and Spillman-Mitscherlich. The stochastic models lead to smaller recommended levels of nitrogen, but the economic benefits of using fully stochastic crop yield functions are small because... |
| Tipo: Journal Article |
Palavras-chave: Cereal rye–ryegrass; Monte Carlo; Nitrogen; Random parameters; Stochastic plateau; Production Economics; Q10; C12; D24. |
| Ano: 2011 |
URL: http://purl.umn.edu/117949 |
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| Blecker, S.W.; STILLINGS, L.L.; AMACHER, M.C.; Ippolito, J.A.; DECRAOPPEO, N.M.. |
| Soil quality indices provide a means of distilling large amounts of data into a single metric that evaluates the soil’s ability to carry out key ecosystem functions. Primarily developed in agroecosytems, then forested ecosystems, we set out to develop and apply an index using the relation between soil organic matter and key soil abiotic and biotic properties in more semi-arid of the Western US arid systems impacted by different geologic mineralization types. We studied these relations in three different mineralization types: serpentine, acid sulfate and Cu/Mo porphyry systems at four different sites in California and Nevada. Soil samples were collected from undisturbed soils in both mineralized and nearby unmineralized terrane as well as waste rock and... |
| Tipo: Article |
Palavras-chave: Nitrogen; Soil. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1489/1/1453.pdf |
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| Medici,Leonardo Oliveira; Gaziola,Salete Aparecida; Varisi,Vanderlei Aparecido; Paula,José Antonio Carmezini de; Ferreira,Renato Rodrigues; Azevedo,Ricardo Antunes. |
| Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cereal; Opaque; Nitrogen; Proteins; Near infrared. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000200009 |
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| Silva,Aurilena de Aviz; Carvalho,Almy Junior Cordeiro de; Freitas,Flávia Paiva de; Pessanha,Patrícia Gomes de Oliveira; Santos,Paulo Cesar dos; Silva,Mírian Peixoto Soares da; Vasconcelos,Tábatha de Souza; Olivares,Fábio Lopes. |
| ABSTRACT: This study examines the effect of inoculation with diazotrophic bacteria and nitrogen fertilization on the growth of micropropagated pineapple cv. 'Vitória' plantlets during the acclimatization period. The experiment was carried out in a greenhouse in Campos dos Goytacazes, in randomized blocks, using a 2x5x5 factorial scheme, with the factors being two types of inocula (absence or presence of a mixture of diazotrophic bacteria that contained Burkholderia sp. UENF 114111, Burkholderia silvatlantica UENF 11711, and Herbaspirillum seropedicae HRC 54), five levels of urea (0, 2, 5, 7, and 10g L-1), and five evaluation periods (30, 60, 90, 120, and 150 days following the planting of plantlets in trays), and with four replications of each treatment.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ananas comosus; Plant growth-promoting bacteria; Nitrogen. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001101952 |
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| Bréchet, Laëtitia; Courtois, Elodie A.; Saint-germain, Thomas; Janssens, Ivan A.; Asensio, Dolores; Ramirez-rojas, Irene; Soong, Jennifer L.; Van Langenhove, Leandro; Verbruggen, Erik; Stahl, Clément. |
| Tropical soils are a major contributor to the balance of greenhouse gas (GHG) fluxes in the atmosphere. Models of tropical GHG fluxes predict that both the frequency of drought events and changes in atmospheric deposition of nitrogen (N) will significantly affect dynamics of soil carbon dioxide (CO2) and methane (CH4) production and consumption. In this study, we examined the combined effect of a reduction in precipitation and an increase in nutrient availability on soil CO2 and CH4 fluxes in a primary French Guiana tropical forest. Drought conditions were simulated by intercepting precipitation falling through the forest canopy with tarpaulin roofs. Nutrient availability was manipulated through application of granular N and/or phosphorus (P) fertilizer to... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Drought; Fertilization; Methane; Nitrogen; Phosphorus; Soil GHG fluxes; Tropical forest. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70694/68903.pdf |
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| Registros recuperados: 425 | |
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