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Registro Completo |
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
17/03/2005 |
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Data da última atualização: |
17/03/2005 |
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Autoria: |
LILIENFEIN, J.; WILCKE, W.; AYARZA, M. A.; VILELA, L.; LIMA, S. do C.; ZECH, W. |
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Título: |
Chemical fractionation of phosphorus, sulphur, and molybdenum in Brazilian savannah oxisols under different land use. |
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Ano de publicação: |
2000 |
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Fonte/Imprenta: |
Geoderma, Amsterdam, v. 96, p. 31-46, 2000. |
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Idioma: |
Inglês |
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Conteúdo: |
In soils, P. S, and Mo occur organically bound or as oxyanions. In oxisols, oxyanions may be strongly sorbed due to the high positive surface charge. The objective of this work was to compare chemical fractions of P. S. and Mo in differently used Oxisols with similar properties in an on-farm experiment. Soil samples (0-0.15m) were taken from three replicate plots of each of conventional tillage (CT) and no-till (NT) maize-soybean and conventional tillage sugarcane (SC) cropping systems, degraded (DP) and productive pastures (PP), Eucalyptus (EU) and Pinus reforestations (PI), and native savannah (CE). The samples were sequentially extracted with (1) 0.5 M NaHCO3, (2) 0.1 M NaOH, (3) 1 M HCI, (4) hot concentrated HCl, and (5) concentrated HClO4/HNO3. In the extracts, inorganic (Pi) and total P, S, and Mo were determined. Organic P (Po) was calculated as total P-Pi. Total concentrations were 333-567 mg P kg (elevado a -1), 231-284 mg S kg (elevado a -1), and 3.2-3.9 mg Mo kg (elevado a -1). The most important fractions in all studied systems were the NaOH fraction for P (38-49% of total P), the HClO4/HNO3 fraction for S (27-35% of total S) and the concentrated HCl fraction for Mo (86-90% of total Mo). The proportion of the more easily extracted NaHCO3+NaOH fractions decreased along the line S>P>Mo. Fertilisation increased plant-availble P and S fractions in CT and NT whereas recalcitrant fraction (concentrated HCl and HClO4/HNO3) remained unchanged. The Pi/Po ratios in NT and CT were higher than CE because fertiliser P mainly accumulated in inorganic P fractions. The pasture soil had lower P concentrations indicating export by grazing. Thus, 12-20 years of land use had marked effects on P. smaller ones on S. and almost none on Mo concentrations and chemical fractions. MenosIn soils, P. S, and Mo occur organically bound or as oxyanions. In oxisols, oxyanions may be strongly sorbed due to the high positive surface charge. The objective of this work was to compare chemical fractions of P. S. and Mo in differently used Oxisols with similar properties in an on-farm experiment. Soil samples (0-0.15m) were taken from three replicate plots of each of conventional tillage (CT) and no-till (NT) maize-soybean and conventional tillage sugarcane (SC) cropping systems, degraded (DP) and productive pastures (PP), Eucalyptus (EU) and Pinus reforestations (PI), and native savannah (CE). The samples were sequentially extracted with (1) 0.5 M NaHCO3, (2) 0.1 M NaOH, (3) 1 M HCI, (4) hot concentrated HCl, and (5) concentrated HClO4/HNO3. In the extracts, inorganic (Pi) and total P, S, and Mo were determined. Organic P (Po) was calculated as total P-Pi. Total concentrations were 333-567 mg P kg (elevado a -1), 231-284 mg S kg (elevado a -1), and 3.2-3.9 mg Mo kg (elevado a -1). The most important fractions in all studied systems were the NaOH fraction for P (38-49% of total P), the HClO4/HNO3 fraction for S (27-35% of total S) and the concentrated HCl fraction for Mo (86-90% of total Mo). The proportion of the more easily extracted NaHCO3+NaOH fractions decreased along the line S>P>Mo. Fertilisation increased plant-availble P and S fractions in CT and NT whereas recalcitrant fraction (concentrated HCl and HClO4/HNO3) remained unchanged. The Pi/Po ratios in NT and ... Mostrar Tudo |
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Thesagro: |
Cerrado; Eucalipto; Reflorestamento. |
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Thesaurus Nal: |
Pinus. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02429naa a2200229 a 4500
001 1568612
005 2005-03-17
008 2000 bl uuuu u00u1 u #d
100 1 $aLILIENFEIN, J.
245 $aChemical fractionation of phosphorus, sulphur, and molybdenum in Brazilian savannah oxisols under different land use.
260 $c2000
520 $aIn soils, P. S, and Mo occur organically bound or as oxyanions. In oxisols, oxyanions may be strongly sorbed due to the high positive surface charge. The objective of this work was to compare chemical fractions of P. S. and Mo in differently used Oxisols with similar properties in an on-farm experiment. Soil samples (0-0.15m) were taken from three replicate plots of each of conventional tillage (CT) and no-till (NT) maize-soybean and conventional tillage sugarcane (SC) cropping systems, degraded (DP) and productive pastures (PP), Eucalyptus (EU) and Pinus reforestations (PI), and native savannah (CE). The samples were sequentially extracted with (1) 0.5 M NaHCO3, (2) 0.1 M NaOH, (3) 1 M HCI, (4) hot concentrated HCl, and (5) concentrated HClO4/HNO3. In the extracts, inorganic (Pi) and total P, S, and Mo were determined. Organic P (Po) was calculated as total P-Pi. Total concentrations were 333-567 mg P kg (elevado a -1), 231-284 mg S kg (elevado a -1), and 3.2-3.9 mg Mo kg (elevado a -1). The most important fractions in all studied systems were the NaOH fraction for P (38-49% of total P), the HClO4/HNO3 fraction for S (27-35% of total S) and the concentrated HCl fraction for Mo (86-90% of total Mo). The proportion of the more easily extracted NaHCO3+NaOH fractions decreased along the line S>P>Mo. Fertilisation increased plant-availble P and S fractions in CT and NT whereas recalcitrant fraction (concentrated HCl and HClO4/HNO3) remained unchanged. The Pi/Po ratios in NT and CT were higher than CE because fertiliser P mainly accumulated in inorganic P fractions. The pasture soil had lower P concentrations indicating export by grazing. Thus, 12-20 years of land use had marked effects on P. smaller ones on S. and almost none on Mo concentrations and chemical fractions.
650 $aPinus
650 $aCerrado
650 $aEucalipto
650 $aReflorestamento
700 1 $aWILCKE, W.
700 1 $aAYARZA, M. A.
700 1 $aVILELA, L.
700 1 $aLIMA, S. do C.
700 1 $aZECH, W.
773 $tGeoderma, Amsterdam$gv. 96, p. 31-46, 2000.
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Embrapa Cerrados (CPAC) |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Cerrados. Para informações adicionais entre em contato com cpac.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
30/01/2008 |
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Data da última atualização: |
30/01/2008 |
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Tipo da produção científica: |
Artigo em Anais de Congresso / Nota Técnica |
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Circulação/Nível: |
-- - -- |
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Autoria: |
AGUIAR, J. L. P. de; SOUSA, T. C. R. de; SILVA, M. J. C. da; FIALHO, J. de F.; VIEIRA, E. A. |
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Afiliação: |
Jozeneida Lúcia Pimenta de Aguiar, CPAC; Tito Carlos Rocha de Sousa, CPAC; Meire Jane Carmo da Silva; Josefino de Freitas Fialho, CPAC; Eduardo Alano Vieira, CPAC. |
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Título: |
Mercado de produtos amiláceos (fécula, polvilho doce e polvilho azedo) na Microrregião Urucuia Grande Sertão. |
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Ano de publicação: |
2007 |
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Fonte/Imprenta: |
In: CONGRESSO BRASILEIRO DA MANDIOCA, 12., 2007, Paranavaí. Mandioca: bioenergia, alimento e renda. Botucatu: CERAT- UNESP, [2007]. 1 CD-ROM. |
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Idioma: |
Português |
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Palavras-Chave: |
Cadeia de produção. |
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Thesagro: |
Agricultura Familiar; Agronegócio. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 00704naa a2200193 a 4500
001 1570589
005 2008-01-30
008 2007 bl uuuu u00u1 u #d
100 1 $aAGUIAR, J. L. P. de
245 $aMercado de produtos amiláceos (fécula, polvilho doce e polvilho azedo) na Microrregião Urucuia Grande Sertão.
260 $c2007
650 $aAgricultura Familiar
650 $aAgronegócio
653 $aCadeia de produção
700 1 $aSOUSA, T. C. R. de
700 1 $aSILVA, M. J. C. da
700 1 $aFIALHO, J. de F.
700 1 $aVIEIRA, E. A.
773 $tIn: CONGRESSO BRASILEIRO DA MANDIOCA, 12., 2007, Paranavaí. Mandioca: bioenergia, alimento e renda. Botucatu: CERAT- UNESP, [2007]. 1 CD-ROM.
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