| |
|
|
|
Registro Completo |
|
Biblioteca(s): |
Embrapa Amazônia Oriental; Embrapa Pantanal. |
|
Data corrente: |
17/12/2001 |
|
Data da última atualização: |
14/09/2010 |
|
Autoria: |
BENCKISER, G.; OTTOW, J. C. G.; SANTIAGO, S.; WATANABE, I. |
|
Título: |
Physicochemical characterization of iron-toxic soils in some Asian countries. |
|
Ano de publicação: |
1982 |
|
Fonte/Imprenta: |
Philippines: IRRI, 1982. |
|
Páginas: |
11 p. |
|
Descrição Física: |
il. |
|
Série: |
(IRRI. Research paper, 85). |
|
Idioma: |
Inglês |
|
Conteúdo: |
High Fe(II) levels caused by low pH and relatively high amounts of active iron and aggravated by a continuous Fe supply from upwelling or lateral seepage from adjacent hills have been blamed for excessive iron uptake. If iron toxicity is induced directly or indirectly by one or more constaints, the same stresses should be shared by soils that show bronzing and/or yellowing. To examine this hypothesis, Physicochemical analyses of soils (up to 40 cm depth) and intoxified leaves were made at different sites in the Philippines, Sri Lanka, Indonesia, China, and Liberia. Soil and plant data were correlated and sites were grouped by principal component and cluster analysis. The following conclusions were drawn: - Although iron-toxic soils were usually slightly acid, there was no correlation between pH and high Fe concentrations in the leaves. - The negative correlations between Fe in the intoxified leaves and active Fe in the soils indicate indirect relationships. - Significant correlations between iron in the rice leaves and cation exchange capacity (CEC) or exchangeable Ca and low P and exchangeable K values are characteristics shared by the soils, indicating the importance of soil nutrient status as a prerequisite for iron toxicity. The effect of a multinutritional soil stress on interactions between iron-reducing bacteria (the main iron-reducing agents in rhizosphere and soil) and rice roots (iron-excluding power and membrane permeability) are discussed and a mechanism for iron intoxification is proposed. MenosHigh Fe(II) levels caused by low pH and relatively high amounts of active iron and aggravated by a continuous Fe supply from upwelling or lateral seepage from adjacent hills have been blamed for excessive iron uptake. If iron toxicity is induced directly or indirectly by one or more constaints, the same stresses should be shared by soils that show bronzing and/or yellowing. To examine this hypothesis, Physicochemical analyses of soils (up to 40 cm depth) and intoxified leaves were made at different sites in the Philippines, Sri Lanka, Indonesia, China, and Liberia. Soil and plant data were correlated and sites were grouped by principal component and cluster analysis. The following conclusions were drawn: - Although iron-toxic soils were usually slightly acid, there was no correlation between pH and high Fe concentrations in the leaves. - The negative correlations between Fe in the intoxified leaves and active Fe in the soils indicate indirect relationships. - Significant correlations between iron in the rice leaves and cation exchange capacity (CEC) or exchangeable Ca and low P and exchangeable K values are characteristics shared by the soils, indicating the importance of soil nutrient status as a prerequisite for iron toxicity. The effect of a multinutritional soil stress on interactions between iron-reducing bacteria (the main iron-reducing agents in rhizosphere and soil) and rice roots (iron-excluding power and membrane permeability) are discussed and a mechanism for iron... Mostrar Tudo |
|
Palavras-Chave: |
Chemophysical properties; Propriedade fisicoquimica; Soils; Teor de ferro; Toxicidade. |
|
Thesagro: |
Ferro; Solo; Toxidez. |
|
Thesaurus Nal: |
Asia; iron; soil; toxicity. |
|
Categoria do assunto: |
-- |
|
Marc: |
LEADER 02308nam a2200313 a 4500
001 1381612
005 2010-09-14
008 1982 bl uuuu u0uu1 u #d
100 1 $aBENCKISER, G.
245 $aPhysicochemical characterization of iron-toxic soils in some Asian countries.
260 $aPhilippines: IRRI$c1982
300 $a11 p.$cil.
490 $a(IRRI. Research paper, 85).
520 $aHigh Fe(II) levels caused by low pH and relatively high amounts of active iron and aggravated by a continuous Fe supply from upwelling or lateral seepage from adjacent hills have been blamed for excessive iron uptake. If iron toxicity is induced directly or indirectly by one or more constaints, the same stresses should be shared by soils that show bronzing and/or yellowing. To examine this hypothesis, Physicochemical analyses of soils (up to 40 cm depth) and intoxified leaves were made at different sites in the Philippines, Sri Lanka, Indonesia, China, and Liberia. Soil and plant data were correlated and sites were grouped by principal component and cluster analysis. The following conclusions were drawn: - Although iron-toxic soils were usually slightly acid, there was no correlation between pH and high Fe concentrations in the leaves. - The negative correlations between Fe in the intoxified leaves and active Fe in the soils indicate indirect relationships. - Significant correlations between iron in the rice leaves and cation exchange capacity (CEC) or exchangeable Ca and low P and exchangeable K values are characteristics shared by the soils, indicating the importance of soil nutrient status as a prerequisite for iron toxicity. The effect of a multinutritional soil stress on interactions between iron-reducing bacteria (the main iron-reducing agents in rhizosphere and soil) and rice roots (iron-excluding power and membrane permeability) are discussed and a mechanism for iron intoxification is proposed.
650 $aAsia
650 $airon
650 $asoil
650 $atoxicity
650 $aFerro
650 $aSolo
650 $aToxidez
653 $aChemophysical properties
653 $aPropriedade fisicoquimica
653 $aSoils
653 $aTeor de ferro
653 $aToxicidade
700 1 $aOTTOW, J. C. G.
700 1 $aSANTIAGO, S.
700 1 $aWATANABE, I.
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Amazônia Oriental (CPATU) |
|
|
Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
URL |
Voltar
|
|
|
| Registros recuperados : 3 | |
| Registros recuperados : 3 | |
|
| Nenhum registro encontrado para a expressão de busca informada. |
|
|
