The importance of humin in soil characterisation: A study on Amazonian soils using different fluorescence techniques

Autor(es)

Tadini, Amanda Maria ^{[1, 2]} ; Nicolodelli, Gustavo ^[2] ; Mounier, Stephane ^[3] ; Montes, Celia Regina ^{[4, 5]} ; Bastos Pereira Milori, Debora Marcondes ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem Sao Carlos, Sao Carlos, SP - Brazil

^[2] EMBRAPA Agr Instrumentat, Sao Carlos, SP - Brazil

^[3] Univ Toulon & Var, Lab PROTEE, EA3819, F-83041 Toulon 9 - France

^[4] Univ Sao Paulo, Ctr Energia Nucl Agr, Piracicaba, SP - Brazil

^[5] Univ Sao Paulo, NUPEGEL, Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 537, p. 152-158, DEC 15 2015.
• Citações Web of Science: 10

Resumo

Soil organic matter (SOM) is a complex mixture of molecules with different physicochemical properties, with humic substances (HS) being the main component as it represents around 20-50% of SOM structure. Soil of the Amazon region is considered one of the larger carbon pools of the world; thus, studies of the humic fractions are important for understanding the dynamics of organic matter (OM) in these soils. The aim of this study was to use laser-induced fluorescence spectroscopy (LIFS) and a combination of excitation-emission matrix (EEM) fluorescence with Parallel Factor Analysis (CP/PARAFAC) to assess the characteristics of humin (HU) extracted from Amazonian soils. The results obtained using LIFS showed that there was an increasing gradient of humification degree with depth, the deeper horizon presenting a higher amount of aromatic groups in the structure of HU. From the EEM, the contribution of two fluorophores with similar behaviour in the structures of HU and whole soil was assessed. Additionally, the results showed that the HU fraction might represent a larger fraction of SOM than previously thought: about 80-93% of some Amazon soils. Therefore, HU is an important humic fraction, thus indicating its role in environmental analysis, mainly in soil analysis. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/03250-2 - Quantificação e dinâmica do carbono associado a horizontes espódicos profundos de solos da Floresta Amazônica, face a possíveis mudanças climáticas
• Beneficiário: Célia Regina Montes
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 13/13013-3 - Caracterização das Substâncias Húmicas extraídas de Solos da Região Amazônica
• Beneficiário: Amanda Maria Tadini
• Modalidade de apoio: Bolsas no Brasil - Doutorado