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Registro Completo |
Biblioteca(s): |
Embrapa Arroz e Feijão. |
Data corrente: |
30/01/2006 |
Data da última atualização: |
14/05/2022 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Autoria: |
VOLLAND-TUDURI, N.; BRUAND, A.; BROSSARD, M.; BALBINO, L. C.; OLIVEIRA, M. I. L. de; MARTINS, E. de S. |
Afiliação: |
NATHALIE VOLLAND-TUDURI; ARY BRUAND; MICHEL BROSSARD; LUIZ CARLOS BALBINO, CNPAF; MARIA INES LOPES DE OLIVEIRA; EDER DE SOUZA MARTINS. |
Título: |
Mass proportion of microaggregates and bulk density in a Brazilian clayey Oxisol. |
Ano de publicação: |
2005 |
Fonte/Imprenta: |
Soil Science Society of America Journal, v. 69, n. 5, p.1559-1564, Sept./Oct. 2005. |
Idioma: |
Inglês |
Conteúdo: |
The physical properties of Brazilian Oxisols are closely related to the development of their microstructure, which typically consists of stable microaggregates >1 mm. There is no model available to predict changes in microstructure in Oxisols. The objective of this work was to relate the proportion of microaggregates to the bulk density (Db) in the soil studied. Five sites of a typic Haplustox under native forest vegetation (two sites) and pasture (three sites) in Rio de Janeiro were sampled. Soil bulk density, sand, silt, and clay content and aggregate-size distribution were measured from the surface to 1.6 m deep in increments of 0.1 m. Thin sections were prepared from undisturbed samples collected in duplicate from 0- to 0.1-, 0.3- to 0.4-, 0.8- to 0.9-, and 1.5- to 1.6-m depths, and backscattered electron scanning images (BESI) were generated. Clay content ranged from 672 to 798 g kg-1 and bulk density between 0.87 and 1.18 g cm-3 among the 80 samples studied. Bulk density was poorly correlated with clay content (R2=0.358) and at any depth was not significantly smaller under native forest vegetation than under pasture. Visual assessment of BESI revealed that soil material corresponded to either microaggregates (<0.1 mm) in loose arrangement or to much larger aggregates. Quantification of BESI from the deepest sampling depth of all soils showed that 96.2 and 95.7% of microaggregates were <0.8 mm with 73.2 and 95.7% between 0.1 and 0.5 mm under native forest vegetation and pasture, respectively. The mass proportion of microaggregates can be estimated using the <0.84-mm soil material that is obtained by dry sieving ( Phi <0.84). Finally, our results showed that Phi <0.84 varied with Db. Linear regression coefficients were calculated for the relationship between Phi <0.84 and the reciprocal of bulk density (1/Db) [ Phi <0.84=1.97 (1/Db) - 1.52, R2=0.82], assuming no interaction between microaggregates and macro aggregates, the porosity of these two structural types was estimated as 0.71 and 0.51, respectively. MenosThe physical properties of Brazilian Oxisols are closely related to the development of their microstructure, which typically consists of stable microaggregates >1 mm. There is no model available to predict changes in microstructure in Oxisols. The objective of this work was to relate the proportion of microaggregates to the bulk density (Db) in the soil studied. Five sites of a typic Haplustox under native forest vegetation (two sites) and pasture (three sites) in Rio de Janeiro were sampled. Soil bulk density, sand, silt, and clay content and aggregate-size distribution were measured from the surface to 1.6 m deep in increments of 0.1 m. Thin sections were prepared from undisturbed samples collected in duplicate from 0- to 0.1-, 0.3- to 0.4-, 0.8- to 0.9-, and 1.5- to 1.6-m depths, and backscattered electron scanning images (BESI) were generated. Clay content ranged from 672 to 798 g kg-1 and bulk density between 0.87 and 1.18 g cm-3 among the 80 samples studied. Bulk density was poorly correlated with clay content (R2=0.358) and at any depth was not significantly smaller under native forest vegetation than under pasture. Visual assessment of BESI revealed that soil material corresponded to either microaggregates (<0.1 mm) in loose arrangement or to much larger aggregates. Quantification of BESI from the deepest sampling depth of all soils showed that 96.2 and 95.7% of microaggregates were <0.8 mm with 73.2 and 95.7% between 0.1 and 0.5 mm under native forest vegetation and... Mostrar Tudo |
Thesagro: |
Cerrado; Solo. |
Thesaurus Nal: |
bulk density; clay fraction; forest soils; grassland soils; image analysis; microaggregates; Oxisols; particle size distribution; sand fraction; silt fraction; soil density; soil physical properties; soil structure; soil types. |
Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
Marc: |
LEADER 03119naa a2200373 a 4500 001 1213861 005 2022-05-14 008 2005 bl uuuu u00u1 u #d 100 1 $aVOLLAND-TUDURI, N. 245 $aMass proportion of microaggregates and bulk density in a Brazilian clayey Oxisol.$h[electronic resource] 260 $c2005 520 $aThe physical properties of Brazilian Oxisols are closely related to the development of their microstructure, which typically consists of stable microaggregates >1 mm. There is no model available to predict changes in microstructure in Oxisols. The objective of this work was to relate the proportion of microaggregates to the bulk density (Db) in the soil studied. Five sites of a typic Haplustox under native forest vegetation (two sites) and pasture (three sites) in Rio de Janeiro were sampled. Soil bulk density, sand, silt, and clay content and aggregate-size distribution were measured from the surface to 1.6 m deep in increments of 0.1 m. Thin sections were prepared from undisturbed samples collected in duplicate from 0- to 0.1-, 0.3- to 0.4-, 0.8- to 0.9-, and 1.5- to 1.6-m depths, and backscattered electron scanning images (BESI) were generated. Clay content ranged from 672 to 798 g kg-1 and bulk density between 0.87 and 1.18 g cm-3 among the 80 samples studied. Bulk density was poorly correlated with clay content (R2=0.358) and at any depth was not significantly smaller under native forest vegetation than under pasture. Visual assessment of BESI revealed that soil material corresponded to either microaggregates (<0.1 mm) in loose arrangement or to much larger aggregates. Quantification of BESI from the deepest sampling depth of all soils showed that 96.2 and 95.7% of microaggregates were <0.8 mm with 73.2 and 95.7% between 0.1 and 0.5 mm under native forest vegetation and pasture, respectively. The mass proportion of microaggregates can be estimated using the <0.84-mm soil material that is obtained by dry sieving ( Phi <0.84). Finally, our results showed that Phi <0.84 varied with Db. Linear regression coefficients were calculated for the relationship between Phi <0.84 and the reciprocal of bulk density (1/Db) [ Phi <0.84=1.97 (1/Db) - 1.52, R2=0.82], assuming no interaction between microaggregates and macro aggregates, the porosity of these two structural types was estimated as 0.71 and 0.51, respectively. 650 $abulk density 650 $aclay fraction 650 $aforest soils 650 $agrassland soils 650 $aimage analysis 650 $amicroaggregates 650 $aOxisols 650 $aparticle size distribution 650 $asand fraction 650 $asilt fraction 650 $asoil density 650 $asoil physical properties 650 $asoil structure 650 $asoil types 650 $aCerrado 650 $aSolo 700 1 $aBRUAND, A. 700 1 $aBROSSARD, M. 700 1 $aBALBINO, L. C. 700 1 $aOLIVEIRA, M. I. L. de 700 1 $aMARTINS, E. de S. 773 $tSoil Science Society of America Journal$gv. 69, n. 5, p.1559-1564, Sept./Oct. 2005.
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Biblioteca(s): |
Embrapa Cerrados. |
Data corrente: |
15/03/1993 |
Data da última atualização: |
15/03/1993 |
Autoria: |
RIBEIRO, J. F.; SANO, S. M.; SILVA, J. A. da. |
Título: |
Chave preliminar de identificacao dos tipos fisionomicos da vegetacao dos cerrados. |
Ano de publicação: |
1981 |
Fonte/Imprenta: |
In: CONGRESSO NACIONAL DE BOTANICA, 32., 1981, Teresina. Anais. Teresina: SBB/UFPI, 1981. |
Páginas: |
p.124-133. |
Idioma: |
Português |
Conteúdo: |
Varios autores ainda discutem a nomenclatura dos tipos fisionomicos ocorrentes na Regiao dos Cerrados. Apesar disso, nao se tem um consenso sobre uma padronizacao dessa monenclatura. Dada essa dificuldade, e proposta uma chave preliminar, com ilustracoes, para os tipos fisionomicos comumente diferenciados, visando facilitar a sua identificacao em trabalhos multidisciplinares. A partir de levantamento bibliografico e trabalho de campo foram identificados e separados os tipos fisionomicos de Mata de Galeria, mata Mesofitica, Cerradao, Cerrado, Campo Cerrado, Campo Sujo, Campo Limpo, Vereda, Campo Rupestre e Campo Murundu, os principais parametros usados na separacao dos tipos fisionomicos foram estrutura da vegetacao e caracteristicas do solo. Com relacao a estrutura da vegetacao foram considerados altura, estratificacao, caducifolia e porcentagem de cobertura arborea. Quanto as caracteristicas do solo foram utilizadas grau de umidade, profundidade e presenca ou nao de afloramento de rochas. |
Thesagro: |
Cerrado; Vegetação. |
Thesaurus NAL: |
vegetation. |
Categoria do assunto: |
-- |
Marc: |
LEADER 01567naa a2200193 a 4500 001 1548296 005 1993-03-15 008 1981 bl --- 0-- u #d 100 1 $aRIBEIRO, J. F. 245 $aChave preliminar de identificacao dos tipos fisionomicos da vegetacao dos cerrados. 260 $c1981 300 $ap.124-133. 520 $aVarios autores ainda discutem a nomenclatura dos tipos fisionomicos ocorrentes na Regiao dos Cerrados. Apesar disso, nao se tem um consenso sobre uma padronizacao dessa monenclatura. Dada essa dificuldade, e proposta uma chave preliminar, com ilustracoes, para os tipos fisionomicos comumente diferenciados, visando facilitar a sua identificacao em trabalhos multidisciplinares. A partir de levantamento bibliografico e trabalho de campo foram identificados e separados os tipos fisionomicos de Mata de Galeria, mata Mesofitica, Cerradao, Cerrado, Campo Cerrado, Campo Sujo, Campo Limpo, Vereda, Campo Rupestre e Campo Murundu, os principais parametros usados na separacao dos tipos fisionomicos foram estrutura da vegetacao e caracteristicas do solo. Com relacao a estrutura da vegetacao foram considerados altura, estratificacao, caducifolia e porcentagem de cobertura arborea. Quanto as caracteristicas do solo foram utilizadas grau de umidade, profundidade e presenca ou nao de afloramento de rochas. 650 $avegetation 650 $aCerrado 650 $aVegetação 700 1 $aSANO, S. M. 700 1 $aSILVA, J. A. da 773 $tIn: CONGRESSO NACIONAL DE BOTANICA, 32., 1981, Teresina. Anais. Teresina: SBB/UFPI, 1981.
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