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Chemical and Spectroscopic Methods for Assessing Subsidence in Florida Histosols
Author(s) -
Volk B. G.,
Schnitzer M.
Publication year - 1973
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1973.03615995003700060027x
Subject(s) - histosol , chemistry , subsidence , degradation (telecommunications) , muck , environmental chemistry , environmental science , geology , soil water , soil science , soil organic matter , geomorphology , telecommunications , structural basin , soil biodiversity , computer science
The extent of subsidence of cultivated histosols in the Everglades of southern Florida can be assessed by chemical and spectroscopic methods. Higher subsidence rates tend to be associated with the following changes in the chemistry of humic acids, the principal constituent of histosols: (i) increases in CO 2 H, phenolic OH, quinone, and ketonic C=O groups; (ii) decreases in aliphatic structures as shown by IR spectra and alcoholic OH groups; and (iii) decreases in molecular complexity as indicated by E 4 /E 6 ratios and possibly by free radical measurements. The chemical reactions involved appear to be mainly oxidative, leading at first to the degradation of aliphatic structures to C=O and CO 2 H groups, and finally to attacking the more stable aromatic structures with degradation to CO 2 and H 2 O. Functional group analysis and measurements of E 4 /E 6 ratios are useful and experimentally simple methods for estimating the degree of degradation of Florida histosols.