Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 10/27/1997
Publication Date: N/A
Technical Abstract: Humic acids (HAs) were isolated from 3 soils amended with composts, animal manure, municipal sewage sludge, and sweet corn residue. Amendments were applied at various levels. HAs were also isolated from soil controls and from each type of amendment. Elemental analysis data show significant differences between soil HA and HA-like substances isolated from the amendments. Minor changes were observed for the amended-soil HAs. Total acidities of amended-soil HAs slightly increased with respect to soil HAs, mainly due to a relative increase of phenolic OH groups. Fluorescence spectra of amended-soil HAs showed increased RFI values following soil amendments, but no major variation of the spectral features. FT-IR spectra of HAs changed slightly according to soil type. Marked changes, however, were observed after amendment application. FT-IR spectra show, in general, increased absorptions in the region of polysaccharides, aliphatic chains and aromatic C=C bonds.