Spectroscopic characterization of humic and fulvic acids in soil aggregates, Brazil

Heliyon

Júlio Cézar Franchini¹  Wesley Machado²  João Tavares Filho³  Maria de Fátima Guimarães⁴ 

[1] Corresponding author.;Agronomy, Universidade Estadual de Londrina, Centro de Ciências Agrárias, Rodovia Celso Garcia Sid, s/n, CEP:86057970, Londrina PR, Brazil;Centro de Ciências Agrárias da Universidade Estadual de Londrina, Rodovia Celso Garcia Sid, s/n, CEP: 86057970 Londrina PR, Brazil;Embrapa Soja, Centro Nacional de Pesquisa em Soja, Rodovia Carlos João Strass, s/n, Acesso Orlando Amaral, Distrito de Warta Caixa Postal: 231 CEP: 86001-970 Londrina PR, Brazil;

关键词: Agriculture;    Soil science;    Humic substances;    Crop science;   

DOI  :  

来源: DOAJ

【 摘 要 】

Agricultural management methods affect organic compounds in the soil. The aim of this study was to characterize humic and fulvic acids using infrared spectroscopy and nuclear magnetic resonance (NMR) in aggregates collected from areas under different crop and soil management systems. Soil samples were collected at depths of 0.00–0.10 m in a trial set up in 1989 with four management systems (no-till, no-till with chiseling every three years, disk harrowing and heavy disking) under two production systems (succession and rotation). In the laboratory, the soil was sieved and separated into two fractions: particle size of 2 mm or more, and less than 2 mm. From each of the samples an aliquot was extracted and the humic and fulvic acids purified for FTIR, UV-VIS and NMR-1H analysis. The results obtained showed that the structural characterization of the humic and fulvic acid fractions were linked to organic matter left on the soil surface, especially where the agricultural system involved species diversity. Aggregates ≥2 mm produce higher NMR, UV-VIS and FTIR spectral magnitudes in aromatic and aliphatic structures than those <2 mm. Aggregates collected from soil under no-till retained their aromatic and aliphatic chemical structures, resulting in higher spectral amplitude.

【 授权许可】

Unknown