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| 12. |  | MARANHÃO, R. L. A.; VIEIRA FILHO, J. E. R. Previdência rural, segurado especial e assistencialismo. Revista de Política Agrícola, Brasília, DF, n. 27, n. 4, p. 134-152, out./nov. 2018 Título em inglês: Rural social pension insurance, special insured and assistencialism.| Biblioteca(s): Embrapa Unidades Centrais. |
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| Registros recuperados : 21 | |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Arroz e Feijão. Para informações adicionais entre em contato com cnpaf.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Arroz e Feijão. |
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Data corrente: |
29/04/2003 |
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Data da última atualização: |
29/04/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
BALBINO, L. C.; BRUAND, A.; BROSSARD, M.; GRIMALDI, M.; HAJNOS, M.; GUIMARAES, M. F. |
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Afiliação: |
LUIZ CARLOS BALBINO, CNPAF. |
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Título: |
Changes in porosity and microaggregation in clayey Ferralsols of the Brazilian Cerrado on clearing for pasture. |
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Ano de publicação: |
2002 |
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Fonte/Imprenta: |
European Journal of Soil Science, v. 53, n. 2, p. 219-230, June 2002. |
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Idioma: |
Inglês |
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Conteúdo: |
Ferrasols have a macrostructure that is weak to moderate and a strong microstructure consisting of near spherical microaggregates. We have studied the evolution of the structure under changing land use in two Ferralsols under a native Cerrado and under pasture after recent clearing by measuring bulk density. We studied the microaggregates characteristics and resulting porosity using scanning electron microscopy and mercury porosimetry, respectively. Microaggregates 50-300 um in diameter are attributed to termites. They were in a much closer arrangement from the surface to 1 m depth under pasture than under Cerrado. Larger microaggregates, 500-1000 um in diameter, that are closely packed, resulted from earthworm activity. They were more numerous under pasture than under Cerrado. Thus within a few years, clearing and grazing have caused a dramatic decrease in microstructure that is one of the rare favourable characteristics of Ferralsols of agriculture. This evolution that affects the subsoil to 80-90 cm cannot be attributed to compaction by mechanical deforestation alone but seems to result from a change in the faunal activity in the faunal activity in the soil. Finally, the packing of the clay particles within the microaggregates was similar whatever the type microaggregate and land use. Our results accord with ealier studies showing that the porosity resulting from clay packing varies little in Ferralsols in which the fine material is mainly kaolinite. |
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Palavras-Chave: |
Densidade; Pasto; Pasture. |
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Thesagro: |
Cerrado; Pastagem; Solo. |
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Thesaurus NAL: |
Ferralsols. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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Marc: |
LEADER 02219naa a2200265 a 4500
001 1210819
005 2022-04-29
008 2002 bl uuuu u00u1 u #d
100 1 $aBALBINO, L. C.
245 $aChanges in porosity and microaggregation in clayey Ferralsols of the Brazilian Cerrado on clearing for pasture.$h[electronic resource]
260 $c2002
520 $aFerrasols have a macrostructure that is weak to moderate and a strong microstructure consisting of near spherical microaggregates. We have studied the evolution of the structure under changing land use in two Ferralsols under a native Cerrado and under pasture after recent clearing by measuring bulk density. We studied the microaggregates characteristics and resulting porosity using scanning electron microscopy and mercury porosimetry, respectively. Microaggregates 50-300 um in diameter are attributed to termites. They were in a much closer arrangement from the surface to 1 m depth under pasture than under Cerrado. Larger microaggregates, 500-1000 um in diameter, that are closely packed, resulted from earthworm activity. They were more numerous under pasture than under Cerrado. Thus within a few years, clearing and grazing have caused a dramatic decrease in microstructure that is one of the rare favourable characteristics of Ferralsols of agriculture. This evolution that affects the subsoil to 80-90 cm cannot be attributed to compaction by mechanical deforestation alone but seems to result from a change in the faunal activity in the faunal activity in the soil. Finally, the packing of the clay particles within the microaggregates was similar whatever the type microaggregate and land use. Our results accord with ealier studies showing that the porosity resulting from clay packing varies little in Ferralsols in which the fine material is mainly kaolinite.
650 $aFerralsols
650 $aCerrado
650 $aPastagem
650 $aSolo
653 $aDensidade
653 $aPasto
653 $aPasture
700 1 $aBRUAND, A.
700 1 $aBROSSARD, M.
700 1 $aGRIMALDI, M.
700 1 $aHAJNOS, M.
700 1 $aGUIMARAES, M. F.
773 $tEuropean Journal of Soil Science$gv. 53, n. 2, p. 219-230, June 2002.
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