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Registros recuperados: 40 | |
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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: Outras publicações técnicas (INFOTECA-E) |
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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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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Qui-minet, Zujaila Nohemy; Coudret, Jérôme; Davoult, Dominique; Grall, Jacques; Mendez‐sandin, Miguel; Cariou, Thierry; Martin, Sophie. |
Made up of calcareous coralline algae, maerl beds play a major role as ecosystem engineers in coastal areas throughout the world. They undergo strong anthropogenic pressures, which may threaten their survival. The aim of this study was to gain insight into the future of maerl beds in the context of global and local changes. We examined the effects of rising temperatures (+3°C) and ocean acidification (−0.3 pH units) according to temperature and pH projections (i.e., the RCP 8.5 scenario), and nutrient (N and P) availability on three temperate maerl species (Lithothamnion corallioides, Phymatolithon calcareum, and Lithophyllum incrustans) in the laboratory in winter and summer conditions. Physiological rates of primary production, respiration, and... |
Tipo: Text |
Palavras-chave: Calcification; Maerl; Nitrate; Ocean acidification; Ocean warming; Phosphate; Photosynthesis; Respiration. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70722/68955.pdf |
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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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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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Ridame, C; Moutin, T; Guieu, C. |
A Saharan soil, considered as a proxy for Saharan aerosols, was used to perform radio-labelled phosphate adsorption experiments using (33)PO(4)(3-): leached particles were exposed to poisoned western Mediterranean seawater for varying lengths of time. The measured adsorption capacity of Saharan dust for phosphate was 0.13 mumol g(-1). Considering this value and an annual Saharan dust deposition of 12.5 t km(-2) year(-1), we show that Saharan particles do not represent a significant sink for seawater phosphate in the western Mediterranean Sea. This result is in agreement with that determined from a similar approach conducted in the eastern basin. As a consequence, the unusual NIP ratio measured in the whole Mediterranean Sea (up to 29) cannot be explained... |
Tipo: Text |
Palavras-chave: Poussières sahariennes; Adsorption; Phosphate; Rapport N/P; Méditerranée; Saharan dust; Adsorption; Phosphate; N/P ratio; Mediterranean Sea. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00321/43254/42985.pdf |
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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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Prata,Fábio; Cardinali,Vanessa Camponez do Brasil; Lavorenti,Arquimedes; Tornisielo,Valdemar Luiz; Regitano,Jussara Borges. |
The sorption of glyphosate by soils occurs due to the inner sphere complex formation with metals of soil oxides, which are related to the soil phosphate adsorption capacity. The aim of this study was to evaluate the effects of increasing rates of phosphorus on sorption and desorption of glyphosate in three soils with different mineralogical attributes. Soils were a Rhodic Kandiudalf, an Anionic Acrudox and a Typic Humaquept. Soil samples were amended with KH2PO4 at equivalent rates of 0; 1,000; 5,000; 20,000 and 50,000 kg ha-1 of P2O5, which are high from the agricultural point of view, but necessary in order to perform sorption and desorption studies. The experimental design consisted of a completely randomized factorial: 2 soils x 5 phosphorus rates and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicide; Retention; Bound residue; Phosphate; Oxides. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000100026 |
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Lema, Anais Kimberley; Latimier, Marie; Nezan, Elisabeth; Fauchot, Juliette; Le Gac, Mickael. |
The factors responsible for inducing the synthesis of toxins and responses from toxic phytoplankton blooms remain unclear. In this study we compare the influence of genotypic (at both the intra and interspecific levels) and environmental factors (nutrient concentration and ratio) on growth (in terms of cell densities) and domoic acid (DA) production in three Pseudo-nitzschia species: P. australis, P.pungens and P.fradulenta. A strong phosphate effect was detected. More precisely, a low initial concentration in phosphate, even at high initial nitrogen and silicate concentrations, induced the highest DA concentrations and the lowest cell densities in all strains/species studied. In contrast, a low initial concentration of nitrogen and silicate combined, with... |
Tipo: Text |
Palavras-chave: Pseudo-nitzschia strains; Domoic acid; Ratio; Phosphate; Nitrogen. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00377/48849/49397.pdf |
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Santos,Hemmannuella Costa; Oliveira,Fábio Henrique Tavares de; Salcedo,Ignácio Hernan; Souza,Adailson Pereira de; Mota Silva,Valério Damásio da. |
The soil P sorption capacity has been studied for many years, but little attention has been paid to the rate of this process, which is relevant in the planning of phosphate fertilization. The purpose of this experiment was to assess kinetics of P sorption in 12 representative soil profiles of the State of Paraíba (Brazil), select the best data fitting among four equations and relate these coefficients to the soil properties. Samples of 12 soils with wide diversity of physical, chemical and mineralogical properties were agitated in a horizontal shaker, with 10 mmo L-1 CaCl2 solution containing 6 and 60 mg L-1 P, for periods of 5, 15, 30, 45, 60, 90, 120, 420, 720, 1,020, and 1,440 min. After each shaking period, the P concentration in the equilibrium... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adsorption; Kinetic equations; Phosphate; Tropical soils; Semi-arid soils. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832011000400024 |
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Menesguen, Alain; Aminot, Alain; Belin, Catherine; Chapelle, Annie; Guillaud, Jean-francois; Joanny, Michel; Lefebvre, Alain; Merceron, Michel; Piriou, Jean-yves; Souchu, Philippe. |
In order to be able to count the cases of coastal eutrophication and to propose methods to monitor as well as to reduce these phenomena, first of all it is necessary to precisely define the word eutrophication itself. Instead of the strict etymological definition, that is to say a progression of the enrichment of a medium, we will rather retain the concept of a state enriched at a point such as it causes harmful effects on the ecosystem, and nuisances to man's activities. Based on the average chemical equations of the organic matter synthesis/degradation in the sea, this operational definition thus puts forwards the harmful consequences of enrichment, i.e. the production of an excessive algal biomass, sometimes unbalanced from the point of view of... |
Tipo: Text |
Palavras-chave: Alexandrium; Phaeocystis; Monostroma; Ulva; Dilution plume; Water trapping; Anoxia; Nitrogen and phosphorus loadings; Red tides; Phytoplankton blooms; Green tides; Eutrophication; Alexandrium; Phaeocystis; Monostroma; Ulva; Panache de dilution; Confinement; Anoxie; Phosphate; Nitrate; Apports terrigènes; Eaux colorées; Blooms phytoplanctoniques; Marées vertes; Eutrophisation. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/rapport-22.pdf |
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Registros recuperados: 40 | |
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