Efecto del material original y del horizonte del suelo sobre la estructura química de las sustancias húmicas extraidas de dos suelos ácidos de bosque de Galicia (NW Spain)
-
1
Universidade de Santiago de Compostela
info
ISSN: 1135-6863
Year of publication: 2004
Issue Title: Ciclo del carbono
Volume: 11
Issue: 2
Pages: 197-206
Type: Article
More publications in: Edafología
Abstract
Humic and fulvic acids were extracted from the surface and a deeper (>45 cm) Ah horizon of two acid forest soils developed from amphibolites and granites, under five different types of vegetation. Elemental analysis and UV-vis and NMR spectroscopy were used to determine the chemical structures. The concentration of humic acid in the soil decreased with increasing depth, whereas that of the fulvic acid increased. The humic substances extracted from the AM soil contained a higher percentage of carbon, had a higher content of alkyl C and a higher concentration of N than those extracted from the GR soil. The content of O-alkyl C decreased with increasing depth. The most marked effect of depth was revealed in the increase in the carbonyl C content, particularly in the content of carboxylic groups. The type of vegetation was not observed to have any effect on the properties of the humic substances.