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Registros recuperados: 44 | |
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Santos,Maria L.S.; Muniz,Kátia; Barros-Neto,Benício; Araujo,Moacyr. |
The Amazon River estuary is notable at the Amazon Continental Shelf, where the presence of the large amount of water originating from the Amazon during the river's falling discharge period was made evident by the low salinity values and high nutrient levels. Even so, the presence of oceanic waters in the shelf area was significant. Dissolved organic nitrogen was the predominant species of the nitrogen cycle phases, followed by total particulate nitrogen, nitrate, ammonium and nitrite. The chlorophyll a data in the eutrophic area indicated that there is sufficient nitrogen in the area to withstand productivity, though dissolved inorganic nitrogen removal processes are faster than regeneration or mineralization. The anomalous amounts of inorganic dissolved... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon Continental Shelf; Nitrogen; Phosphate; Mathematical modeling. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000400011 |
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Souchie,Edson L.; Saggin-Júnior,Orivaldo J.; Silva,Eliane M.R.; Campello,Eduardo F.C.; Azcón,Rosario; Barea,Jose M.. |
Communities of P-solubilizing bacteria, fungi and arbuscular mycorrhizal fungi, were evaluated in two different ecosystems. Samplings taken from two areas of Atlantic forest, in Paraty - RJ, Brazil, one with a secondary forest and the other with a grass pasture were studied. Four growth media: GL (glucose and yeast extract), GES (glucose, soil extract, KNO3, CaCl2, MgSO4, NaCl, FeEDTA and micronutrients solution), GAGES (glucose, soil extract, arabinose, glycerol, CaCl2, MgSO4 and NaCl) and GELP (glucose, soil extract, yeast extract, peptone, CaCl2, MgSO4 and NaCl) were evaluated for the isolation of P-solubilizing microorganisms. The identification of P-solubilizing bacteria was based on 16 S rDNA sequence analysis, while the identification of... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphate; Enterobacteriaceae; Atlantic Forest; Glomeromycota; Soil microorganisms. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652006000100016 |
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FARIAS,JÚLIA G.; BERNARDY,KATIELI; SCHWALBERT,RAÍSSA; DEL FRARI,BIANCA K.; MEHARG,ANDREW; CAREY,MANUS; MARQUES,ANDERSON C.R.; SIGNES-PASTOR,ANTONIO; SAUSEN,DARLENE; SCHORR,MÁRCIO R.W.; TAVARES,MIRIAN S.; NICOLOSO,FERNANDO T.. |
ABSTRACT A hydroponic experiment was carried out to investigate the effect of phosphorus (P) nutrition on arsenic (As) uptake and translocation within the seedlings of rice cultivars. The experiment occurred in three stages: I 5 days of acclimatization (nutritive solution); II 10 days under P (0.0 and 0.09 mM) and As (0.0 and 100 mM) treatments; III 5 days under recovery. The As exposure had significant effect reducing dry weights of shoots or roots, resulted in elevated concentrations of As in shoot tissues. BR-IRGA 409 showed the highest susceptibility to As in biomass production and root system parameters regardless the P level. This cultivar showed contrasting responses of As translocation to shoot tissue dependent on P levels, with the highest As... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mineral nutrition; Oryza sativa; Phosphate; Arsenic uptake.. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000100163 |
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Nahas,Ely. |
ABSTRACTThis work studied the acid phosphatase (APase) activity from culture medium (extracellular, eAPase) and mycelial extract (intracellular, iAPase) ofAspergillus niger F111. The influence of fungus growth and phosphate concentration of the media on the synthesis and secretion of phosphatase was demonstrated. The effects of pH, substrate concentration and inorganic and organic compounds added to the reaction mixture on APase activity were also studied. Both enzymes were repressed by high concentrations of phosphate. Overexpression of iAPase in relation to eAPase was detected; iAPase activity was 46.1 times higher than eAPase. The maximal activity of eAPase was after 24h of fungus growth and for iAPase was after 96h. Optimal pH and substrate... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enzyme inhibitors; Molybdenum; Overexpression; Phosphate; Soil chemical characteristics. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132015000500658 |
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Srivastav,Ajai K.; Tiwari,P.R.; Srivastav,S.K.; Sasayama,Y.; Suzuki,N.. |
Vitamin D3 (100 ng 100 g body weight-l day-l) was administered intraperitoneally (ip) to the freshwater mud eel Amphipnous cuchia kept in artificial freshwater, calcium-free freshwater, low-calcium freshwater (0.2 mmol/l CaCl2) or calcium-rich freshwater (13.4 mmol/l CaCl2) for 15 days. Analyses of serum calcium and phosphate levels were performed on days 1, 3, 5, 10 and 15 after the beginning of the experiment (six eels from each group at each interval). Administration of vitamin D3 elevated the serum calcium [maximum elevation occurred at day 10 in artificial freshwater (vehicle: 10.55 ± 0.298, vitamin D: 13.90 ± 0.324), low-calcium freshwater (vehicle: 11.17 ± 0.220, vitamin D: 12.98 ± 0.297) and calcium-rich freshwater (vehicle: 11.24 ± 0.373, vitamin... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Vitamin D3; Calcium; Phosphate; Mud eel; Teleost. |
Ano: 1997 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100014 |
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Silva,Paulo da; Nahas,Ely. |
The diversity of bacterial isolates from soil in response to different plants (control, Brachiaria ruziziensis and Cajanus cajan), fertilization (control, simple superphosphate and rock phosphate) and liming (with and without lime) was evaluated. Phenotypic and physiological characteristics of the isolates were recorded and organized in a file to identify the bacteria. Among the isolates, 95% were Gram-positive and 5% Gram-negative rods. Soil cultivated with B. ruziziensis favored the nonsporing Gram-positive and Gram-negative rods compared to soils with C. cajan or uncultivated. Number of spore-forming Gram-positive rods were higher in plots with superphosphate than in unfertilized soil or soil fertilized with rock phosphate. In unfertilized plots, larger... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacteria; Phosphate; Brachiaria ruziziensis; Cajanus cajan; Liming. |
Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000400005 |
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Mishra,Shruti; Dubey,R.S.. |
The effect of arsenite (As2O3) in situ on the level of the phosphate pool and activities of phosphohydrolytic enzymes was examined in rice (Oryza sativa L.) seedlings grown for 5-20 d in sand cultures. The effects were manifested via a decline in phosphate content and inhibition of the activities of key phosphatases. Application of 50 µM As2O3 in situ resulted in 34 to 77% inhibition of acid phosphatase activity in roots and about 38 to 50% inhibition of activity in shoots of 15-20-d-old seedlings. Similarly, alkaline phosphatase activity was inhibited in shoots under in situ As (III) toxicity. Varietal as well as organ specific differences were observed in the response of inorganic pyrophosphatase activity to in situ As (III) treatment. A moderately toxic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Arsenite; Chloroplast; Mitochondria; Oryza sativa; Phosphate; Phosphatases. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202008000100003 |
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Paparazzo,Flavio E.; Alder,Viviana A.; Schloss,Irene R.; Bianchi,Alejandro; Esteves,Jose L.. |
The Drake Passage (DP) links the Southern Pacific and Atlantic Oceans, and acts as a physical narrowing for the largest current of the World Ocean, the Antarctic Circumpolar Current (ACC). This result in a constriction of the main circumpolar fronts related to the ACC: the Subantarctic Front, the Polar Front, the Southern Antarctic Circumpolar Current Front and the Continental Water Boundary Front. Previous studies showed that the DP is a high-nutrient low-chlorophyll (HNLC) region, but studies on the interannual and seasonal macronutrients' fluctuations in relation with chlorophyll and frontal areas in the DP are scarce. This study analyzes the spatial and temporal trends of nitrate, phosphate, and silicate on surface samples from 113 oceanographic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrate; Phosphate; Silicate; Chlorophyll-a; Temperature; Salinity; Antarctic fronts; Antarctic zones; Seasonal variation; Interannual variation. |
Ano: 2016 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2016000100004 |
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Alvarez,José M; Pasian,Claudio; Lal,Rattan; López,Rafael; Fernández,Manuel. |
ABSTRACT Containerized ornamental plant production is facing several environmental challenges. One of them is to replace the widely used, but with questionable sustainability, peat based substrates and another is to avoid water contamination by chemicals leaching from the nursery. Therefore, as have been verified that petunia and pelargonium plants can be produced in peat-based growing media partially replaced by vermicompost (V) and biochar (B) without decreasing commercial quality, this study has focused on analyzing the leachate from a standard peat-based substrate as a control, used for producing these two ornamental species, and those from the same substrate to which different proportions in volume of V (10% and 20%) and B (4% and 12%) have been... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Petunia hybrida; Pelargonium peltatum; Peat replacement; Water contamination; Nitrate; Phosphate. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-05362019000100047 |
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SOARES, W. V.; MACEDO, M. C. M.; VILELA, L.; SOUZA, O. C. de. |
Um experimento no campo foi conduzido num Latossolo Roxo Alico muito argiloso, fase cerradao, em Campo Grande - MS, durante 66 meses (1978- 1984), com os seguintes objetivos: Obter a curva de resposta da Brachiaria decumbens ao fosforo e estimar os niveis criticos de fosforo no solo para o estabecimento e a manutencao de pastagem com essa graminea. Os tratamentos constaram de sete doses de fosforo: 0,40, 80, 160, 320, 640 e 1280kg/ha de P205 como superfosfato triplo, em parcelas de 7x5 m, num delineamento de blocos ao acaso com quatro repeticoes. Dez dias antes da aplicacao dos tratamentos, 2,6t/ha de calcario dolomitico foram incorporadas a 20 cm profundidade. Incluiu-se nos tratamentos adubacao basica constituida de: 50, 20, 50, 5 e 1 kg/ha,... |
Tipo: Folhetos |
Palavras-chave: Cultivar Basilisk; Phosphate; Basilisk; Brazilian savannas; Feed grasses; Fertilization; Latosol; Pasture; Phosphorius; Planta gramínea; Red latosol; Savanna; Adubação; Brachiaria Decumbens; Cerrado; Fosfato; Fósforo; Gramínea Forrageira; Latossolo Roxo; Pastagem; Solo; Ferralsols; Fertilizer application; Forage; Fertilizers; Phosphorus; Soil; Varieties. |
Ano: 1999 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/546467 |
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PEREIRA, J. R.; FARIA, C. M. B. de. |
Avaliacao da eficiencia e efeito residual de diversos fosfatos em Latossolo Vermelho Amarelo do submedio Sao Francisco. Constituiu-se de dois experimentos, o primeiro foi avaliada a eficiencia dos seguintes fosfatos na produtividade do milho var. Centralmex: catalao moido, catalao 350, catalao 600, catalao tratado termicamente, patos moidos; patos 250, patos 600, patos tratado termicamente, araxa moido e araxa tratado termicamente. Foi avaliado, tambem, o efeito residual desses fosfatos atraves de dois ciclos da cultura do milho. O segundo expeimento foi realizado com as mesmas caracteristicas do anterior. Como fontes de fosforo foram usados os seguintes produtos: termofosfato goisfertil; fosfato RNC, dapinho, fosfatos parcialmente acidulados fosforico. |
Tipo: Parte de livro |
Palavras-chave: Variety; Soils; Fertility; Phosphate; Fertilidade; Fosfato; Milho; Variedade; Solo; Zea Mays; Corn. |
Ano: 1988 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/132825 |
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MENDONÇA, J. F. B.; GONCALVES, C. A.. |
Procurou-se selecionar forrageira de corte superiores em produtividade e valor nutritivo. Foram avaliadas quanto a producao de materia seca, teores de proteina bruta, calcio e fosforo ea realcao colmo/folha, doze gramineas de corte tratadas com 0,40, 80 e 120kg de P2O5/ha. Durante o periodo de dois anos (9 cortes), foram testadas, onze cultivares de capim-elefante (Pennisetum purpureum Schum.) e uma de capim-venezuela (Tripsacum australe). O capim-elefante cv. Cameroon, destacou-se como sendo o tratamento mais eficiente, com o nivel de 80kg de P2O5/ha. |
Tipo: Folhetos |
Palavras-chave: Forrageira; Brasil; Rondonia; Porto Velho; Forage grasses cut; Fertilization; Phosphate; Adubação; Fosfato; Gramínea; Brazil. |
Ano: 1988 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/697954 |
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Registros recuperados: 44 | |
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