Data/hora: 04/06/2024 13:28:17

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 30/03/1999
Data da última atualização: | 30/03/1999
Autoria: | LILIENFEIN, J.; WILCKE, W.; NEUFELDT, M.; AYARZA, M. A.; ZECH, W.
Título: | Land-use effects on organic carbon, nitrogen, and sulphur concentrations in macroaggregates of differently textured Brazilian oxisols.
Ano de publicação: | 1998
Fonte/Imprenta: | Journal of Plant Nutrition and Soil Science, Berlin, v.161, n.2, p.165-171, 1998.
Idioma: | Inglês
Conteúdo: | The objective of this study was to assess the influence of land use on soil aggregate size distribution and the consequences for organic C,N, and S concentrations in bulk soil and macroaggregates. The properties of a loamy and a clayey Oxisol used for continuos cropping, pasture and reforestation were compared with those of the native savannah ("Cerrado"). We measured aggregate size fractionation, C,N, and S concentrations in bulk soil, small (0,25-2mm, SMA), and large macroaggregates (2-8mm, LMA), and carried out a mineralization experiment with intact and crushed LMA. The aggregate size distribution of pastures was not different from native Cerrado. Reforestation and plowing caused higher percentages of smaller aggregates which was more pronounced in the loamy than in the clayey soil. Total concentrations of C,N, and S were higher in the clayey (C: 21.5-23.3 g kg; N:1.2-1.4 g kg; S: 178-213 mg kg) than in the loamy soil (C: 7.8-10.3 g kg; N 0.5-0.7 g kg; S: 87-132 mg kg). LMA of the loamy soil had higher C,N and S concentrations than the bulk soil. SMA and both macroaggregate fractions of the clayey soil did differ from the bulk soil. 71% of potentially mineralizable N in LMA of the loamy soil were only mineralized after aggregate disruption. In contrast, there were only small differences between crushed and intact LMA of the clayey soil. The loamy soil would require a more soil conserving system like no-till or crop-pasture rotation to improve sustainability.
Palavras-Chave: | Brasil; Sulphur.
Thesagro: | Carbono; Cerrado; Enxofre; Estrutura do Solo; Nitrogênio; Uso da Terra.
Thesaurus Nal: | Brazil; carbon; land use; nitrogen; soil structure.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (11683-1) - UPC - SP - -- - CRI4759 -  - CRI4759 - DIS