|
|
Registro Completo |
Biblioteca(s): |
Embrapa Cerrados. |
Data corrente: |
16/02/2000 |
Data da última atualização: |
16/02/2000 |
Autoria: |
NEUFELDT, H.; AYARZA, M. A.; RESCK, D. V. S.; ZECH, W. |
Título: |
Distribution of water-stable aggregates and aggregating agents in Cerrado Oxisols. |
Ano de publicação: |
1999 |
Fonte/Imprenta: |
Geoderma, Amsterdam, v.93, p.85-99, 1999. |
Idioma: |
Inglês |
Conteúdo: |
The effects of structural changes on Cerrado Oxisols in Brazil after land-use change are still insufficiently studied. Therefore, topsoil samples of loamy and clayey Cerrado Oxisols under crop pasture and reforestation were fractionated using a wet-sieving procedure to obtain the distribution of water-stable aggregates and compared to samples from natural savanna. The results were correlated to organic and inorganic soil compounds to identify the main aggregating agents and discussed in relation to changes in the pore-size distribution of the soils. Clayey soils showed a significantly higher macro-aggregation than loamy soils. Compared to natural savanna, macro-aggregation was clearly reduced at the crop sites, whereas aggregation of soils under pasture and reforestation was only slightly affected. In both the clayey and the loamy soils, bonding of polysaccharides was the main aggregating agent. In the clayey soils, liming was also very important for disaggregation by weakening the electrostatic forces between positively and negativeley charged soil compounds, whereas in the loamy soils, binding of macro-aggregates by roots was significant. The introduction of crop-pasture rotations was therefore proposed to take advantage of the strong rooting and polysaccharide production of pastures. Management-induced disaggregation strongly affected the pore-size distribution by compacting the soils. Thereby, macro-porosity was reduced and the ampunt of meso-pores was increased, while micro-porosity was unaffected from management and only differed between the two substrates. Considering the low pore space at plant-available matrix potentials typical of Cerrado Oxisols, the increase might be important for annual crops during the frequent dry spells in the rainy season. MenosThe effects of structural changes on Cerrado Oxisols in Brazil after land-use change are still insufficiently studied. Therefore, topsoil samples of loamy and clayey Cerrado Oxisols under crop pasture and reforestation were fractionated using a wet-sieving procedure to obtain the distribution of water-stable aggregates and compared to samples from natural savanna. The results were correlated to organic and inorganic soil compounds to identify the main aggregating agents and discussed in relation to changes in the pore-size distribution of the soils. Clayey soils showed a significantly higher macro-aggregation than loamy soils. Compared to natural savanna, macro-aggregation was clearly reduced at the crop sites, whereas aggregation of soils under pasture and reforestation was only slightly affected. In both the clayey and the loamy soils, bonding of polysaccharides was the main aggregating agent. In the clayey soils, liming was also very important for disaggregation by weakening the electrostatic forces between positively and negativeley charged soil compounds, whereas in the loamy soils, binding of macro-aggregates by roots was significant. The introduction of crop-pasture rotations was therefore proposed to take advantage of the strong rooting and polysaccharide production of pastures. Management-induced disaggregation strongly affected the pore-size distribution by compacting the soils. Thereby, macro-porosity was reduced and the ampunt of meso-pores was increased, while m... Mostrar Tudo |
Thesagro: |
Cerrado; Estrutura do Solo; Uso da Terra. |
Thesaurus Nal: |
Ferralsols; land use; soil structure. |
Categoria do assunto: |
-- |
Marc: |
LEADER 02389naa a2200229 a 4500 001 1555056 005 2000-02-16 008 1999 bl --- 0-- u #d 100 1 $aNEUFELDT, H. 245 $aDistribution of water-stable aggregates and aggregating agents in Cerrado Oxisols. 260 $c1999 520 $aThe effects of structural changes on Cerrado Oxisols in Brazil after land-use change are still insufficiently studied. Therefore, topsoil samples of loamy and clayey Cerrado Oxisols under crop pasture and reforestation were fractionated using a wet-sieving procedure to obtain the distribution of water-stable aggregates and compared to samples from natural savanna. The results were correlated to organic and inorganic soil compounds to identify the main aggregating agents and discussed in relation to changes in the pore-size distribution of the soils. Clayey soils showed a significantly higher macro-aggregation than loamy soils. Compared to natural savanna, macro-aggregation was clearly reduced at the crop sites, whereas aggregation of soils under pasture and reforestation was only slightly affected. In both the clayey and the loamy soils, bonding of polysaccharides was the main aggregating agent. In the clayey soils, liming was also very important for disaggregation by weakening the electrostatic forces between positively and negativeley charged soil compounds, whereas in the loamy soils, binding of macro-aggregates by roots was significant. The introduction of crop-pasture rotations was therefore proposed to take advantage of the strong rooting and polysaccharide production of pastures. Management-induced disaggregation strongly affected the pore-size distribution by compacting the soils. Thereby, macro-porosity was reduced and the ampunt of meso-pores was increased, while micro-porosity was unaffected from management and only differed between the two substrates. Considering the low pore space at plant-available matrix potentials typical of Cerrado Oxisols, the increase might be important for annual crops during the frequent dry spells in the rainy season. 650 $aFerralsols 650 $aland use 650 $asoil structure 650 $aCerrado 650 $aEstrutura do Solo 650 $aUso da Terra 700 1 $aAYARZA, M. A. 700 1 $aRESCK, D. V. S. 700 1 $aZECH, W. 773 $tGeoderma, Amsterdam$gv.93, p.85-99, 1999.
Download
Esconder MarcMostrar Marc Completo |
Registro original: |
Embrapa Cerrados (CPAC) |
|
Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
URL |
Voltar
|
|
Registros recuperados : 86 | |
41. | | DINKELMEYER, H.; LEHMANN, J.; KAISER, K.; TEIXEIRA, W. G.; RENCK, A.; ZECH, W. Fate of applied N fertilizer in mixed cropping systems in the central Amazon. In: CONGRESSO BRASILEIRO DE SISTEMAS AGROFLORESTAIS, 3., 2000, Manaus. Sistemas agroflorestais: manejando a biodiversidade e compondo a paisagem rural - resumos expandidos. Manaus: Embrapa Amazonia Ocidental, 2000. p. 196-197.Tipo: Artigo em Anais de Congresso |
Biblioteca(s): Embrapa Amazônia Ocidental. |
| |
47. | | LILIENFEIN, J.; WILCKE, W.; VILELA, L.; LIMA, S. do C.; THOMAS, R.; ZECH, W. Effect of no-tillage and conventional tillage systems on the chemical composition of soil solid phase and soil solution of brazilian savanna oxisols. Journal of Plant Nutrition and Soil Science, Berlin, v. 163, p. 411-419, 2000.Biblioteca(s): Embrapa Cerrados. |
| |
52. | | LEHMANN, J.; SILVA JUNIOR, J. P. da; STEINER, C.; NEHLS, T.; ZECH, W.; GLASER, B. Nutrient availability and leaching in an archaeological Anthrosol and a Ferralsol of the Central Amazon basin: fertilizer, manure and charcoal amendments. Plant and Soil, v. 249, p. 343-357, 2003.Tipo: Artigo em Periódico Indexado | Circulação/Nível: Internacional - A |
Biblioteca(s): Embrapa Amazônia Ocidental. |
| |
54. | | LEHMANN, J.; SCHROTH, G.; TEIXEIRA, W.; WOLFGANG ZECH, W.; CRAVO, M. da S. Nutrient and water dynamics in a multi-strata agroforestry system. In: CONGRESSO BRASILEIRO EM SISTEMAS AGROFLORESTAIS, 2., 1998, Belém, PA. Sistemas agroflorestais no contexto da qualidade ambiental e competitividade: resumos expandidos. Belém, PA: Embrapa-CPATU, 1998. p. 38-41.Tipo: Artigo em Anais de Congresso |
Biblioteca(s): Embrapa Amazônia Ocidental. |
| |
57. | | AMELUNG, W.; MAARTIUS, C.; GARCIA, M.; KUEPER, U.; ULBRICH, D.; ZECH, W. Organic matter in termite mounds of an Amazonian rain forest. In: SHIFT-WORKSHOP, 3., 1998, Manaus. Program, abstracts of presentations and posters... Hamburg: GKSS, 1998. p. C50.Tipo: Resumo em Anais de Congresso |
Biblioteca(s): Embrapa Amazônia Ocidental. |
| |
58. | | AMELUNG, W.; MARTIUS, C.; GARCIA, M. V.; KUEPER, U.; ULBRICH, D.; ZECH, W. Organic matter in termite mounds of an Amazonian rain forest. In: SHIFT - WORKSHOP, 3., 1998, Manaus. Proceedings... Bonn: BMBF, 1998. p. 493-496.Tipo: Artigo em Anais de Congresso |
Biblioteca(s): Embrapa Amazônia Ocidental. |
| |
59. | | RENZ, T. E.; NEUFELDT, H.; AYARZA, M. A.; RESCK, D. V. S.; ZECH, W. Microbial biomass, microbial activity, and carbon pools under different land-use systems in the Brazilian cerrados. 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. p.187-197.Biblioteca(s): Embrapa Cerrados. |
| |
Registros recuperados : 86 | |
|
Nenhum registro encontrado para a expressão de busca informada. |
|
|