Fourier Transform Infrared (FTIR) Spectroscopy of humic substances shows major components through different peaks. FTIR spectrum of humic acid (HA) showed bands at 3246 cm-1 (H-bonded OH), 1721 cm-1 (C=O of COOH, C=O stretch of ketonic C=O), 1634 cm-1 (COO-, C=O of carbonyl and quinone) and 1102 cm-1 (C-O stretch or OH deformation of COOH). Whereas, fulvic acid (FA) showed peaks at 3497cm-1 (H bonded OH), 2925- 2855cm-1 (aliphatic C-H stretch), 2415 cm-1 (extended aliphatic C-H stretch), 1648cm-1 (COO-, C=O of carbonyl and quinone), 1158 cm-1 (aliphatic C-H). Humic acid gives prominent peaks of aromatic components whereas, aliphatic peaks for FA. The distinctiveness of humic substances was influenced by land use management and climatic parameters (temperature and rainfall). | Fourier transform infrared FTIR spectroscopy of soil humic and fulvic acids extracted from paddy land use system
