Data/hora: 02/06/2024 03:07:36

Provedor de dados: | 90
País: | Brazil
Título: | The use of total luminescence spectroscopy in the investigation of the effects of different rice management practices on humic substances of a planosol
Autores: | Olendzki,Rodrigo Nogueira; Ignácio,Andréia Christina; Mangrich,Antonio Salvio.
Data: | 2009-10-01
Ano: | 2009
Palavras-chave: | Fulvic acid; Humic acid; Total luminescence spectroscopy.
Resumo: | In the Earth's carbon cycle, C stocks in the soil are higher than in vegetation and atmosphere. Maintaining and conserving organic C concentrations in the soil by specific management practices can improve soil fertility and productivity. The aim of this study was to evaluate the impact of agricultural management techniques and influence of water regime (flooded or drained) on the structure of humic substances by excitation/emission matrix fluorescence. Six samples of a Planosol (Planossolo by the Brazilian System of Soil Classification) were collected from a rice field. Humic substances (HS) were extracted from flooded and drained soil under different agricultural management techniques: conventional tillage, reduced tillage and grassland. Two peaks at a long emission wavelength were observed in the EEM spectra of HA whereas those of the corresponding FA contained a unique fluorophore at an intermediate excitation/emission wavelength pair (EEWP) value. The fluorescence intensity measured by total luminescence (FI TL) of HA was lower than that of the corresponding FA. A comparison of all samples (i.e., the HA values compared to each other) revealed only slight differences in the EEWP position, but the FI TL values were significantly different. In this soil, anoxic conditions and reduced tillage (little plowing) seem to favor a higher degree of humification of the soil organic matter compared with aerated conditions and conventional tillage.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500008
Editor: | Sociedade Brasileira de Ciência do Solo
Relação: | 10.1590/S0100-06832009000500008
Formato: | text/html
Fonte: | Revista Brasileira de Ciência do Solo  v.33 n.5 2009
Fonte: | info:eu-repo/semantics/openAccess