USE OF C-13 NMR AND FTIR FOR ELUCIDATION OF DEGRADATION PATHWAYS DURING NATURAL LITTER DECOMPOSITION AND COMPOSTING .1. EARLY-STAGE LEAF DEGRADATION

Oxidative degradation of plant tissue leads to the formation of natura l dissolved organic carbon (DOG) and humus, Infrared (IR) and C-13 nuc lear magnetic resonance (NMR) spectrometry have been used to elucidate the chemical reactions of the early stages of degradation that give r ise to DOC derived from litter and compost, The results of this study indicate that oxidation of the lignin components of plant tissue follo ws the sequence of O-demethylation, and hydroxylation followed by ring -fission, chain-shortening, and oxidative removal of substituents, Oxi dative ring-fission leads to the formation of carboxylic acid groups o n the cleaved ends of the rings and, in the process, transforms phenol ic groups into aliphatic alcoholic groups,The carbohydrate components are broken down into aliphatic hydroxy acids and aliphatic alcohols.