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| André, E.. |
| Foi observado um evento de afloramento de algas nocivas e morte maciça de peixes e interrupção temporária das actividades turísticas na lagoa de Bilene, Moçambique em 2007. O presente estudo pretende fazer uma caracterização da hidrodinâmica e do estado trófico desta lagoa e compreender processos que resultam em afloramentos de algas tóxicas. Entre Julho de 2010 e Agosto de 2011, foram realizados oito campanhas de colheitas de dados de CTD incluindo a concentração de oxigénio em água,cobrindo um ciclo anual. Os resultados revelaram que a Lagoa de Bilene contem duas sub-bacias, uma a sul, maior em extensão geográfica mas menos profunda, e uma bacia a norte, com menor extensão geográfica mas mais profunda. As massas de água tem uma caracterização típica com... |
| Tipo: Journal Contribution |
Palavras-chave: Eutrophication; Fertilization (biological); Salinity; Oxygen; Temperature; Oxygen deficiency; Temperature. |
| Ano: 2012 |
URL: http://hdl.handle.net/1834/5143 |
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| Gubiani,Paulo Ivonir; Müller,Eduardo Augusto; Somavilla,André; Zwirtes,Anderson Luiz; Mulazzani,Rodrigo Pivoto; Marchesan,Enio. |
| ABSTRACT Water and oxygen deficiencies in the soybean crop cultivated on lowland soils are an important topic of research. The objective of this study was to investigate changes in water and oxygen supply and soybean yield caused by soil management in lowland soils. A soybean crop was grown under four soil conditions: no-tillage (NT), chiseling (CH), ridge tillage on no-tillage (NTR), and ridge tillage on chiseling (CHR). Soil bulk density, total porosity, macro- and microporosity, air permeability, and saturated hydraulic conductivity were measured at 0.05, 0.15, 0.25, and 0.35 m depths. Soil volumetric water content was monitored at the same depths every 30 min during the soybean cycle. The transpiration coefficient was calculated from volumetric water... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water stress; Oxygen deficiency; Water table. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100414 |
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| Thomas,André Luís; Sodek,Ladaslav. |
| Flooding leads to hypoxia, a stress to which symbiotic N2 fixation is especially sensitive. The response of fully nodulated soybean plants to a 21-day period of flooding was studied by measurements of growth parameters and xylem transport of organic nitrogenous components to the shoot, in the presence and absence of NO3- and NH4+ in the medium. Flooding was found to seriously impair N2 fixation, irrespective of the N source, as indicated by strongly reduced xylem ureide levels. In the absence of a source of N, growth was strongly reduced during flooding while accumulation of N in the shoot was virtually abolished. Flooding in the presence of 5 mM NO3- or NH4+ led to the accumulation of total N in the shoot but only NO3- promoted increases in total dry... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Anaerobiosis; Oxygen deficiency. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1677-04202005000300003 |
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