Humic acids from a range of Italian soils and the residual suspended organic material (light fraction litter) associated with them have been studied by pyrolysis gas chromatography mass spectrometry, solid state nuclear magnetic resonance spectroscopy, and infra-red spectroscopy. Although the major vegetation types on the soils differ considerably, spectra of humic acids from soils with different major vegetation types were similar. Because no relationship between humic acid structure and major vegetation type was observed, gross assumptions about humic acid structure should not be drawn from a knowledge of macro-vegetation types on soils. Light fraction litter in the soils from minor vegetation may be more significant in affecting the eventual structure of the humic acids.
No takes yet. Share an insight, caveat, or question.
Amalfitano et al. (1995) studied this question.