Data/hora: 18/06/2024 00:09:36

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 21/03/2005
Data da última atualização: | 21/03/2005
Autoria: | BALBINO, L. C.; BRUAND, A.; BROSSARD, M.; GUIMARÃES, M. de F.
Título: | Comportement de la phase argileuse lors de la dessiccation dans des ferralsols microagrégés du Brésil: rôle de la microstructure et de la matière organique.
Ano de publicação: | 2001
Fonte/Imprenta: | Comptes Rendus de l'Academie des Sciences Paris, v. 332, p. 673-680, 2001.
Idioma: | Francês
Conteúdo: | Behaviour of the clay fraction during desiccation in microagggregated Ferralsols from Brazil: role of microestructure and organic matter. The physical properties of the microaggregates of Ferralsols are still under discussion. Two sites were selected for study: in each site one soil under a native savannah (Cerrado) and another one under pasture were studied. Samples were analysed in the laboratory by using scanning electron microscopy and mercury porosimetry and by measuring the water content at -0.1 and 1.5 MPa potential. Results showed the presence of microaggregates 50 to 300 mm in size and bigger ones 500 to 1000  mm in size. The latter were often packed in dense volumes 2 to 20 mm in size, which were numerous in the top soil under pasture. These dense volumes are casts and would result from an imbalance in the faunal population as a consequence of deforestation. Results showed also a shinkage of the clayed phase for drying and this shrinkage increased with the carbon content of the soil. These results showed that microaggregates are not rigid fabrics and the significant role of organic matter in physical properties of the soils studied.
Thesagro: | Argila; Carbono; Cerrado; Solo.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (25771-1) - UPC - SP - -- - CRI6685 -  - CRI6685 - DIS