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| 14. |  | 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. |
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| 16. | | FUHRMANN, S.; NEUFELDT, H.; WESTERHOF, R.; AYARZA, M. A.; SILVA, J. E. da; ZECH, W. Soil organic carbon, carbohydrates, amino sugars, and potentially mineralizable nitrogen under different land-use systems in oxisols of 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.110-122.| Biblioteca(s): Embrapa Cerrados. |
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| 19. | | 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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| 20. | | 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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 | 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: |
15/07/1999 |
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Data da última atualização: |
15/07/1999 |
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Autoria: |
NEUFELDT, H.; AYARZA, M. A.; RESCK, D. V. S.; ZECH, W. |
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Título: |
Distribution of water-stable aggregates and aggregating agents 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.51-63. |
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Idioma: |
Inglês |
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Conteúdo: |
The effects of land-use change on the structure of Oxisols in the Brazilian savannas (also known as the Cerrados) are still insuficiently understood. We therefore studied loamy and clayey Oxisols under natural savanna, crop, pastures, and reforestation to (1) quantify management-induced changes in the quantity of water-stable aggregates, (2) identify the main aggregating agents, and (3) correlate aggregation with changes in pore-size distribution. Clayey soils showed a significantly higher macroaggregation than did loamy soils. Compared with natural savanna, macroaggregation was clearly reduced under crops, whereas aggregation of soils under pasture and tree plantations was only slightly affected. In both clavey and loamy soils, polysaccharides formed the main aggregating agent. In the clayey soils, lime very effectively disaggregated the soils by weakening the electrostatic forces between positivily and negatively charged soil compounds. In the loamy soils, the role of roots in binding macroaggregates was significant. Because pastures provide strong rooting and higt polysaccharide production, we recommend introducing crop/pasture rotations. Management-induced disaggregation strongly affected the pore-size distribution by compacting the soils, and thus reducing macroporosity and increasing mesoporosity. Microporosity, however, was unaffected by management and differed only between the two substrates. Considering the Oxisols' typically low pore space at plant-available matrix potentials, the increase in mesoporosity may be important for annual crops during the frequent dry spells in the rainy season. MenosThe effects of land-use change on the structure of Oxisols in the Brazilian savannas (also known as the Cerrados) are still insuficiently understood. We therefore studied loamy and clayey Oxisols under natural savanna, crop, pastures, and reforestation to (1) quantify management-induced changes in the quantity of water-stable aggregates, (2) identify the main aggregating agents, and (3) correlate aggregation with changes in pore-size distribution. Clayey soils showed a significantly higher macroaggregation than did loamy soils. Compared with natural savanna, macroaggregation was clearly reduced under crops, whereas aggregation of soils under pasture and tree plantations was only slightly affected. In both clavey and loamy soils, polysaccharides formed the main aggregating agent. In the clayey soils, lime very effectively disaggregated the soils by weakening the electrostatic forces between positivily and negatively charged soil compounds. In the loamy soils, the role of roots in binding macroaggregates was significant. Because pastures provide strong rooting and higt polysaccharide production, we recommend introducing crop/pasture rotations. Management-induced disaggregation strongly affected the pore-size distribution by compacting the soils, and thus reducing macroporosity and increasing mesoporosity. Microporosity, however, was unaffected by management and differed only between the two substrates. Considering the Oxisols' typically low pore space at plant-available matrix... Mostrar Tudo |
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Thesagro: |
Cerrado; Estrutura do Solo; Oxisol; Uso da Terra. |
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Thesaurus NAL: |
Ferralsols; land use; soil structure. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02445naa a2200253 a 4500
001 1545398
005 1999-07-15
008 1999 bl uuuu u00u1 u #d
100 1 $aNEUFELDT, H.
245 $aDistribution of water-stable aggregates and aggregating agents in oxisols of the Brazilian cerrados.
260 $c1999
300 $ap.51-63.
520 $aThe effects of land-use change on the structure of Oxisols in the Brazilian savannas (also known as the Cerrados) are still insuficiently understood. We therefore studied loamy and clayey Oxisols under natural savanna, crop, pastures, and reforestation to (1) quantify management-induced changes in the quantity of water-stable aggregates, (2) identify the main aggregating agents, and (3) correlate aggregation with changes in pore-size distribution. Clayey soils showed a significantly higher macroaggregation than did loamy soils. Compared with natural savanna, macroaggregation was clearly reduced under crops, whereas aggregation of soils under pasture and tree plantations was only slightly affected. In both clavey and loamy soils, polysaccharides formed the main aggregating agent. In the clayey soils, lime very effectively disaggregated the soils by weakening the electrostatic forces between positivily and negatively charged soil compounds. In the loamy soils, the role of roots in binding macroaggregates was significant. Because pastures provide strong rooting and higt polysaccharide production, we recommend introducing crop/pasture rotations. Management-induced disaggregation strongly affected the pore-size distribution by compacting the soils, and thus reducing macroporosity and increasing mesoporosity. Microporosity, however, was unaffected by management and differed only between the two substrates. Considering the Oxisols' typically low pore space at plant-available matrix potentials, the increase in mesoporosity may 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 $aOxisol
650 $aUso da Terra
700 1 $aAYARZA, M. A.
700 1 $aRESCK, D. V. S.
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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