Studies of litter and acid insoluble soil organic matter fractions using ¹³C‐cross polarization nuclear magnetic resonance spectroscopy with magic angle spinning

Abstract

Cross polarization carbon-1 3 nuclear magnetic resonance spectroscopy with magic angle spinning (CP-MASS) was used to analyse for various forms of carbon in soils, a moss peat, hydrochloric acid insoluble residues from soils and peat, and litter from beech and pine trees. The chemical composition of the litters was also investigated by conventional techniques.The results show that hydrolysis with hydrochloric acid extraction removes nearly all oxygenated alkyl carbon from the soils used. It is shown that humification pathways in which carbohydrates are incorporated into humic substances via nonhydrolysable linkages are not important for the soils investigated in this work.CP-MASS data suggest that the percentage of aromatic carbon in pine leaves increases with increase in ageing time. The results for the beech leaves are not sharply defined.

Characterization of organic matter in a forest soil of coastal British Columbia by NMR and pyrolysis-field ionization mass spectrometry

“…The spectrum of the litterfall (Fig. la) which consisted almost entirely of senescent Douglas-fir needles is similar to that reported for fresh conifer litterfall or L horizons (Nord6n and Berg, 1990;Wilson et al, 1983;Zech et al 1987; 1992). Alkyl C (0-48 ppm) accounts for 24.8% of the total area, and 0-and di-0-alkyl C (448-110 ppm) for 59.0% (Table 5).…”

“…The relative intensity of 0-and di-0-alkyl C decreases to 52.9%, while intensity from 110 to 210ppm increases and that of the aliphatic region remains unchanged. Similar changes in intensity distribution observed by Zech et al (1987Zech et al ( , 1992 and Wilson et al (1983), indicate that some decomposition has occurred in the needle litter, mainly by loss of carbohydrates. Decomposition has progressed much further in the H horizon (Fig.…”

Application of 13C NMR spectroscopy to characterize organic chemical components of decomposing coarse woody debris from different climatic regions

“…The positive correlations observed here of lignin-C and AUR with the decay class (Table 3) are consistent with the results of Preston et al (1997) and suggest that lignin is a major component of AUR in wood. The loss of O-alkyl-C and polysaccharide-C was associated with a loss of carbohydrates, such as holocellulose (Wilson et al 1983). The positive association of lignin-C with nitrogen content in decaying CWD (Table 3) may be due to the formation of nitrogenous lignin-like substances as secondary compounds, as suggested by Berg (1986) and Takeda and Abe (2001).…”

COMPARISON OF 13C CPMAS NMR AND CHEMICAL TECHNIQUES FOR MEASURING THE DEGREE OF DECOMPOSITION IN VIRGIN AND CULTIVATED PEAT PROFILES

“…Several recent studies have examined techniques for characterizing peat (L6vesque and Dinel 1977peat (L6vesque and Dinel , 1978peat (L6vesque and Dinel , 1982L6vesque and Mathur 1979;It'vesque et al 1981;Schnizer andDesjardins 1965, 1966;Schniuer and L6vesque 1979 (Kaila 1956) (Lucas 1970 Wilson et al 1983a, b; Hammond et al 1985), whole soils (Preston and Ripmeester 1983;Wilson et al 1983a, b), composts (Pfeffer et al 1984;Piotrowski et al 1984;Preston et al 1986), forages (Eflosen et al 1984), wood (Kolodzieski et al 1982) …”