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Registro Completo |
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
16/07/1999 |
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Data da última atualização: |
16/07/1999 |
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Autoria: |
NEUFELDT, H.; SILVA, J. E. da; AYARZA, M. A.; ZECH, W. |
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Título: |
Phosphorus fractions under different land-use systems in oxisols of the Brazilian cerrados. |
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Ano de publicação: |
1999 |
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Fonte/Imprenta: |
In: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999. |
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Páginas: |
p.146-158. |
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Idioma: |
Inglês |
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Conteúdo: |
We examined whole-soil samples and particle-size fractions to study the distribution of different phosphorus (P) fractions after land-use change from native savanna to crops, pastures, and reforestation on clayey and loamy Oxisols of the Brazilian savannas. Phosphorus was extracted sequentially, according to a modified hedley procedure, into inorganic and organic P (NaOH-extractable Pi and Po, respectively), and recalcitrant P (Phc1 and Pres). Under natural conditions of strong P deficiency, over 60% of NaOH-extractable P was organic, reflecting the high contribuint of Po to plant nutrition. Fertilization elevated inorganic Po. The increase of inorganic P forms from fertilizer P was greatest in the Pi and lowest in the Pres fractions. After fertilization, the reforested sites maintained high NaOH-extractable P through efficient recycling, whereas at the crop and pasture sites, P tended to accumulate in recalcitrant forms. Possibly, the adsorption of P to oxyhydroxides was reduced at the more acid reforested sites by complexation of Fe and Al oxides with organic acids. The ratio of NaOH-extractable Pi to Po appeared to effectively reflect the P status of the land-use systems and P deficiency increased in ascending order from native savanna > pasture > reforestation > crop, independently of soil type. The particle-size separates reflected P transformations along a biological and mineralogical gradient, which is discussed with respect to origin and distribution of natural and fertilizer P forms. That is, (1) P in particle-size separates was enriched in the clay and depleted in the sand fractions such that 70%-87% of total P was bound in the clay; (2) residual P increased relatively at the expense of HCl-extractable P with decreasing particle-size, indicating a continuously stronger adsorption to oxyhydroxides; (3) the proportions of organic P were generally lowest in the 20-50-um fraction because P in particulate organic matter was already depleted and transformed into microbially mediated Po, which was enriched in the clay and silt fractions; (4) fertilizer P accumulated in the 20-50-um fraction and was subsequently transferred to the silt and clay fractions but remained largely in inorganic form. MenosWe examined whole-soil samples and particle-size fractions to study the distribution of different phosphorus (P) fractions after land-use change from native savanna to crops, pastures, and reforestation on clayey and loamy Oxisols of the Brazilian savannas. Phosphorus was extracted sequentially, according to a modified hedley procedure, into inorganic and organic P (NaOH-extractable Pi and Po, respectively), and recalcitrant P (Phc1 and Pres). Under natural conditions of strong P deficiency, over 60% of NaOH-extractable P was organic, reflecting the high contribuint of Po to plant nutrition. Fertilization elevated inorganic Po. The increase of inorganic P forms from fertilizer P was greatest in the Pi and lowest in the Pres fractions. After fertilization, the reforested sites maintained high NaOH-extractable P through efficient recycling, whereas at the crop and pasture sites, P tended to accumulate in recalcitrant forms. Possibly, the adsorption of P to oxyhydroxides was reduced at the more acid reforested sites by complexation of Fe and Al oxides with organic acids. The ratio of NaOH-extractable Pi to Po appeared to effectively reflect the P status of the land-use systems and P deficiency increased in ascending order from native savanna > pasture > reforestation > crop, independently of soil type. The particle-size separates reflected P transformations along a biological and mineralogical gradient, which is discussed with respect to origin and distribution of natural and f... Mostrar Tudo |
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Thesagro: |
Cerrado; Composto Orgânico; Fósforo; Fracionamento; Uso da Terra. |
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Thesaurus Nal: |
fractionation; land use; organic compounds; phosphorus. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 03118naa a2200277 a 4500
001 1545407
005 1999-07-16
008 1999 bl uuuu u00u1 u #d
100 1 $aNEUFELDT, H.
245 $aPhosphorus fractions under different land-use systems in oxisols of the Brazilian cerrados.
260 $c1999
300 $ap.146-158.
520 $aWe examined whole-soil samples and particle-size fractions to study the distribution of different phosphorus (P) fractions after land-use change from native savanna to crops, pastures, and reforestation on clayey and loamy Oxisols of the Brazilian savannas. Phosphorus was extracted sequentially, according to a modified hedley procedure, into inorganic and organic P (NaOH-extractable Pi and Po, respectively), and recalcitrant P (Phc1 and Pres). Under natural conditions of strong P deficiency, over 60% of NaOH-extractable P was organic, reflecting the high contribuint of Po to plant nutrition. Fertilization elevated inorganic Po. The increase of inorganic P forms from fertilizer P was greatest in the Pi and lowest in the Pres fractions. After fertilization, the reforested sites maintained high NaOH-extractable P through efficient recycling, whereas at the crop and pasture sites, P tended to accumulate in recalcitrant forms. Possibly, the adsorption of P to oxyhydroxides was reduced at the more acid reforested sites by complexation of Fe and Al oxides with organic acids. The ratio of NaOH-extractable Pi to Po appeared to effectively reflect the P status of the land-use systems and P deficiency increased in ascending order from native savanna > pasture > reforestation > crop, independently of soil type. The particle-size separates reflected P transformations along a biological and mineralogical gradient, which is discussed with respect to origin and distribution of natural and fertilizer P forms. That is, (1) P in particle-size separates was enriched in the clay and depleted in the sand fractions such that 70%-87% of total P was bound in the clay; (2) residual P increased relatively at the expense of HCl-extractable P with decreasing particle-size, indicating a continuously stronger adsorption to oxyhydroxides; (3) the proportions of organic P were generally lowest in the 20-50-um fraction because P in particulate organic matter was already depleted and transformed into microbially mediated Po, which was enriched in the clay and silt fractions; (4) fertilizer P accumulated in the 20-50-um fraction and was subsequently transferred to the silt and clay fractions but remained largely in inorganic form.
650 $afractionation
650 $aland use
650 $aorganic compounds
650 $aphosphorus
650 $aCerrado
650 $aComposto Orgânico
650 $aFósforo
650 $aFracionamento
650 $aUso da Terra
700 1 $aSILVA, J. E. da
700 1 $aAYARZA, M. A.
700 1 $aZECH, W.
773 $tIn: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999.
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Embrapa Cerrados (CPAC) |
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| Registros recuperados : 86 | |
| 81. |  | AYARZA, M. A.; THOMAS, R.; ZECH, W.; NEUFELDT, H.; WESTRHOF, R. LILIENFEIN, J.; FREIBAUER, A.; SILVA, J. E. da. Soil indicators of sustainable agropastoral systems. In: CONGRESSO BRASILEIRO DE CIENCIA DO SOLO, 27., 1999, Brasilia, DF. [Ciencia do solo e qualidade de vida: anais]. [Planaltina: Embrapa Cerrados, 1999]. Sessao de posteres 1. Resumo.| Biblioteca(s): Embrapa Cerrados. |
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| 82. | | STEINER, C.; TEIXEIRA, W. G.; LEHMANN, J.; GLASER, B.; ARRUDA, M. R. de; ZECH, W.; BLUM, W. E. H. Slash and char as alternative to slash and burn - soil charcoal amendments maintain soil fertility and establish a carbon sink. In: INTERNATIONAL AGRICHAR INITIATIVE (IAI) 2007 CONFERENCE, 2007, Terrigal, Australia. [Abstracts]. Terrigal: IAI, 2007. p. 32-33.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Amazônia Ocidental. |
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| 83. | | TEIXEIRA, W. G.; SCHROTH, G.; VILLANI, E. de A.; FACCIN, O. P.; CORREIA, F. W. S.; CRAVO, M. D. S.; HUWE, B.; ZECH, W. Fluxos de água e de nutrientes como indicadores da estabilidade de diferentes sistemas de uso da terra na Amazônia. Boletim Informativo SBCS, Campinas, v. 21, n. 3, p. 105-107, 1996.| Tipo: Artigo em Periódico Indexado |
| Biblioteca(s): Embrapa Amazônia Ocidental. |
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| 84. | | LILIENFEIN, J.; FREIBAUER, A.; NEUFELDT, H.; WESTERHOF, R.; AYARZA, M. A.; SILVA, J. E. da; RESCK, D. V. S.; ZECH, W. Influence of land-use on the distribution of water stable aggregates and P status of sandy and clayey cerrado oxisols, Brazil. In: SIMPOSIO SOBRE O CERRADO, 8.; INTERNATIONAL SYMPOSIUM ON TROPICAL SAVANNAS, 1., 1996, Brasilia, DF. Biodiversidade e producao sustentavel de alimentos e fibras nos Cerrados: anais... Planaltina: EMBRAPA-CPAC, 1996. p.323-328.| Biblioteca(s): Embrapa Cerrados. |
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| 85. | | SCHROTH, G.; TEIXEIRA, W. G.; VILLANI, E.; FACCIN, P. O.; HAAG, D.; WOLF, M. A.; CORREIA, F. W. S.; SILVA, L. F. da; SEIXAS, R.; ZECH, W. Single-tree effects in agroforestry with perennial crops - an approach to the optimisation of tropical land use systems. In: SHIFT - WORKSHOP, 3., 1998, Manaus. Proceedings... Bonn: BMBF, 1998. p. 453-460.| Tipo: Artigo em Anais de Congresso |
| Biblioteca(s): Embrapa Amazônia Ocidental. |
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| 86. | | SCHROT, G.; TEIXEIRA, W. G.; VILLANI, E.; FACCIN, P. O.; HAAG, D.; WOLF, M.; CORREIA, F. W. S.; SILVA, L. F. da; SEIXAS, R.; ZECH, W. Single-tree effects in agroforestry with perennial crops - an approach to the optimization of tropical land-use systems. In: SHIFT-WORKSHOP, 3., 1998, Manaus. Program, abstracts of presentations and posters... Hamburg: GKSS, 1998. p. P27.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Amazônia Ocidental. |
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| Registros recuperados : 86 | |
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| Nenhum registro encontrado para a expressão de busca informada. |
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